diff --git a/KnowledgeBaseCline.md b/KnowledgeBaseCline.md
index d2662f1..feecac8 100644
--- a/KnowledgeBaseCline.md
+++ b/KnowledgeBaseCline.md
@@ -48,4 +48,3 @@ Ho docker installato, compose v2 (docker cmpose senza trattino)
 
 Il progetto si trova in `/opt/pechub`
 
-Il servizio deve essere esposto su 0.0.0.0 e prevedere l'esposizione anche col dominio pechub.it
\ No newline at end of file
diff --git a/backend/app/api/v1/messages.py b/backend/app/api/v1/messages.py
index 407c2e3..36370dd 100644
--- a/backend/app/api/v1/messages.py
+++ b/backend/app/api/v1/messages.py
@@ -860,6 +860,64 @@ async def get_attachment_preview_url(
         }
 
 
+# ─── Feature 7b: Serve allegato inline per preview ───────────────────────────
+
+@router.get("/{message_id}/attachments/{attachment_id}/inline")
+async def inline_attachment(
+    message_id: uuid.UUID,
+    attachment_id: uuid.UUID,
+    current_user: CurrentUser,
+    db: DB,
+):
+    """
+    Serve l'allegato con Content-Disposition: inline per la preview nel browser.
+
+    Legge il file da MinIO internamente e lo restituisce attraverso il backend,
+    evitando i problemi di accessibilita' con i presigned URL di MinIO in ambienti Docker.
+    Supporta PDF e immagini; per altri tipi restituisce 404.
+    """
+    await _resolve_message(message_id, current_user, db)
+
+    result = await db.execute(
+        select(Attachment).where(
+            Attachment.id == attachment_id,
+            Attachment.message_id == message_id,
+        )
+    )
+    attachment = result.scalar_one_or_none()
+    if not attachment:
+        raise NotFoundError(f"Allegato {attachment_id} non trovato")
+
+    content_type = attachment.content_type or "application/octet-stream"
+    filename = attachment.filename.replace('"', "'")
+
+    try:
+        from miniopy_async import Minio
+
+        client = Minio(
+            endpoint=settings.minio_endpoint,
+            access_key=settings.minio_access_key,
+            secret_key=settings.minio_secret_key,
+            secure=settings.minio_use_ssl,
+        )
+        response = await client.get_object(settings.minio_bucket, attachment.storage_path)
+        data = await response.content.read()
+        response.close()
+        return StreamingResponse(
+            iter([data]),
+            media_type=content_type,
+            headers={
+                "Content-Disposition": f'inline; filename="{filename}"',
+                "Content-Length": str(len(data)),
+            },
+        )
+    except Exception as e:
+        from app.core.logging import get_logger
+        logger = get_logger(__name__)
+        logger.error(f"Errore inline allegato {attachment_id}: {e}")
+        raise NotFoundError("File non disponibile al momento")
+
+
 # ─── Feature 8: Stampa/export HTML ────────────────────────────────────────────
 
 @router.get("/{message_id}/print")
diff --git a/frontend/src/components/ComposeModal/ComposeModal.tsx b/frontend/src/components/ComposeModal/ComposeModal.tsx
new file mode 100644
index 0000000..f944907
--- /dev/null
+++ b/frontend/src/components/ComposeModal/ComposeModal.tsx
@@ -0,0 +1,598 @@
+import { useState, useRef, useMemo, useEffect } from 'react'
+import { useForm, useFieldArray } from 'react-hook-form'
+import {
+  Send,
+  X,
+  Plus,
+  AlertCircle,
+  Paperclip,
+  Upload,
+  Filter,
+  Minus,
+  Maximize2,
+  Minimize2,
+} from 'lucide-react'
+import { useQuery, useMutation } from '@tanstack/react-query'
+import toast from 'react-hot-toast'
+import { Button } from '@/components/ui/Button'
+import { Input } from '@/components/ui/Input'
+import { Label } from '@/components/ui/Label'
+import { RichTextEditor } from '@/components/RichTextEditor/RichTextEditor'
+import { sendApi } from '@/api/send.api'
+import { mailboxesApi } from '@/api/mailboxes.api'
+import { virtualBoxesApi } from '@/api/virtual_boxes.api'
+import { getErrorMessage } from '@/api/client'
+import { useComposeStore } from '@/store/compose.store'
+import type { MessageResponse } from '@/types/api.types'
+
+// ─── Tipi ─────────────────────────────────────────────────────────────────────
+
+interface MailboxSelectItem {
+  id: string
+  email_address: string
+  display_name: string | null
+  status: string
+  fromVbox?: boolean
+}
+
+interface ComposeFormValues {
+  mailbox_id: string
+  to_addresses: { value: string }[]
+  cc_addresses: { value: string }[]
+  subject: string
+}
+
+// ─── Utility ──────────────────────────────────────────────────────────────────
+
+const MAX_FILE_SIZE = 20 * 1024 * 1024
+
+function formatFileSize(bytes: number): string {
+  if (bytes < 1024) return `${bytes} B`
+  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`
+  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`
+}
+
+function htmlToText(html: string): string {
+  if (!html || html === '<p></p>') return ''
+  const div = document.createElement('div')
+  div.innerHTML = html
+  return div.textContent || div.innerText || ''
+}
+
+function buildInitialBody(replyTo?: MessageResponse | null, forwardOf?: MessageResponse | null): string {
+  if (replyTo) {
+    const date = new Date(replyTo.received_at || replyTo.created_at).toLocaleDateString('it-IT')
+    return [
+      '<p></p>',
+      '<p></p>',
+      '<hr>',
+      `<p><strong>In risposta al messaggio del ${date}</strong></p>`,
+      `<p>Da: ${replyTo.from_address || ''}</p>`,
+      `<p>A: ${replyTo.to_addresses?.join(', ') || ''}</p>`,
+      `<p>Oggetto: ${replyTo.subject || ''}</p>`,
+    ].join('')
+  }
+  if (forwardOf) {
+    const date = new Date(forwardOf.received_at || forwardOf.sent_at || forwardOf.created_at).toLocaleDateString('it-IT')
+    const bodyContent = forwardOf.body_text
+      ? `<pre style="white-space:pre-wrap;font-family:inherit">${forwardOf.body_text}</pre>`
+      : ''
+    return [
+      '<p></p>',
+      '<p></p>',
+      '<hr>',
+      `<p><strong>Messaggio inoltrato</strong></p>`,
+      `<p>Da: ${forwardOf.from_address || ''}</p>`,
+      `<p>A: ${forwardOf.to_addresses?.join(', ') || ''}</p>`,
+      `<p>Data: ${date}</p>`,
+      `<p>Oggetto: ${forwardOf.subject || ''}</p>`,
+      bodyContent,
+    ].join('')
+  }
+  return ''
+}
+
+// ─── Form interno (rimontato ogni volta che cambia il messaggio) ───────────────
+
+interface ComposeFormProps {
+  replyTo: MessageResponse | null
+  forwardOf: MessageResponse | null
+  onClose: () => void
+}
+
+function ComposeForm({ replyTo, forwardOf, onClose }: ComposeFormProps) {
+  const fileInputRef = useRef<HTMLInputElement>(null)
+  const [showCc, setShowCc] = useState(false)
+  const [attachments, setAttachments] = useState<File[]>([])
+  const [bodyHtml, setBodyHtml] = useState<string>(() =>
+    buildInitialBody(replyTo, forwardOf)
+  )
+
+  const {
+    register,
+    control,
+    handleSubmit,
+    formState: { errors },
+  } = useForm<ComposeFormValues>({
+    defaultValues: {
+      mailbox_id: replyTo?.mailbox_id || forwardOf?.mailbox_id || '',
+      to_addresses: replyTo ? [{ value: replyTo.from_address || '' }] : [{ value: '' }],
+      cc_addresses: [],
+      subject: replyTo
+        ? `Re: ${replyTo.subject || ''}`
+        : forwardOf
+          ? `Fwd: ${forwardOf.subject || ''}`
+          : '',
+    },
+  })
+
+  const { fields: toFields, append: appendTo, remove: removeTo } = useFieldArray({ control, name: 'to_addresses' })
+  const { fields: ccFields, append: appendCc, remove: removeCc } = useFieldArray({ control, name: 'cc_addresses' })
+
+  const { data: mailboxesData, isLoading: mailboxesLoading } = useQuery({
+    queryKey: ['mailboxes'],
+    queryFn: () => mailboxesApi.list(),
+  })
+
+  const { data: vboxMailboxes = [], isLoading: vboxMailboxesLoading } = useQuery({
+    queryKey: ['virtual-boxes', 'my-mailboxes'],
+    queryFn: () => virtualBoxesApi.getMyMailboxes(),
+  })
+
+  const sendMutation = useMutation({
+    mutationFn: (args: { data: Parameters<typeof sendApi.sendMultipart>[0]; files: File[] }) =>
+      sendApi.sendMultipart(args.data, args.files),
+    onSuccess: (job) => {
+      toast.success(`PEC inviata! Job ID: ${job.id.slice(0, 8)}...`)
+      onClose()
+    },
+    onError: (error) => {
+      toast.error(getErrorMessage(error))
+    },
+  })
+
+  const activeCaselle = useMemo((): MailboxSelectItem[] => {
+    const regularActive: MailboxSelectItem[] = (
+      mailboxesData?.items.filter((m) => m.status === 'active') || []
+    ).map((m) => ({
+      id: m.id,
+      email_address: m.email_address,
+      display_name: m.display_name,
+      status: m.status,
+      fromVbox: false,
+    }))
+
+    const regularIds = new Set(regularActive.map((m) => m.id))
+
+    const vboxActive: MailboxSelectItem[] = vboxMailboxes
+      .filter((m) => m.status === 'active' && !regularIds.has(m.id))
+      .map((m) => ({
+        id: m.id,
+        email_address: m.email_address,
+        display_name: m.display_name,
+        status: m.status,
+        fromVbox: true,
+      }))
+
+    return [...regularActive, ...vboxActive]
+  }, [mailboxesData, vboxMailboxes])
+
+  const isLoadingMailboxes = mailboxesLoading || vboxMailboxesLoading
+
+  const handleFileAdd = (files: FileList | null) => {
+    if (!files) return
+    const valid: File[] = []
+    for (const file of Array.from(files)) {
+      if (file.size > MAX_FILE_SIZE) {
+        toast.error(`"${file.name}" supera il limite di 20 MB`)
+      } else {
+        valid.push(file)
+      }
+    }
+    if (valid.length) setAttachments((prev) => [...prev, ...valid])
+  }
+
+  const removeAttachment = (idx: number) => {
+    setAttachments((prev) => prev.filter((_, i) => i !== idx))
+  }
+
+  const onSubmit = async (formData: ComposeFormValues) => {
+    const toAddresses = formData.to_addresses.map((t) => t.value.trim()).filter((v) => v.length > 0)
+    if (toAddresses.length === 0) {
+      toast.error('Inserisci almeno un destinatario')
+      return
+    }
+    await sendMutation.mutateAsync({
+      data: {
+        mailbox_id: formData.mailbox_id,
+        to_addresses: toAddresses,
+        cc_addresses: formData.cc_addresses.map((c) => c.value.trim()).filter((v) => v.length > 0),
+        subject: formData.subject,
+        body_text: htmlToText(bodyHtml),
+        body_html: bodyHtml,
+        reply_to_message_id: replyTo?.id,
+      },
+      files: attachments,
+    })
+  }
+
+  return (
+    <form onSubmit={handleSubmit(onSubmit)} noValidate className="flex flex-col gap-0 h-full">
+      {/* Corpo scrollabile */}
+      <div className="flex-1 overflow-y-auto px-4 py-3 space-y-3">
+        {/* Avviso informativo */}
+        <div className="rounded-md border border-blue-200 bg-blue-50 p-2.5 flex items-start gap-2">
+          <AlertCircle className="h-3.5 w-3.5 text-blue-600 mt-0.5 flex-shrink-0" />
+          <p className="text-xs text-blue-700">
+            L'invio avviene tramite il server PEC della casella selezionata.
+          </p>
+        </div>
+
+        {/* Allegati del messaggio inoltrato */}
+        {forwardOf && forwardOf.has_attachments && (
+          <div className="rounded-md border border-amber-200 bg-amber-50 p-2.5 flex items-start gap-2">
+            <Paperclip className="h-3.5 w-3.5 text-amber-600 mt-0.5 flex-shrink-0" />
+            <p className="text-xs text-amber-700">
+              Il messaggio originale contiene allegati. Scaricali e aggiungili qui manualmente.
+            </p>
+          </div>
+        )}
+
+        {/* Casella mittente */}
+        <div className="space-y-1">
+          <Label className="text-xs">Casella mittente *</Label>
+          {isLoadingMailboxes ? (
+            <div className="h-8 rounded-md border bg-muted animate-pulse" />
+          ) : activeCaselle.length === 0 ? (
+            <div className="rounded-md border border-destructive/50 bg-destructive/10 p-2 text-xs text-destructive">
+              Nessuna casella PEC attiva disponibile.
+            </div>
+          ) : (
+            <>
+              <select
+                className="flex h-8 w-full rounded-md border border-input bg-background px-3 py-1 text-sm focus:outline-none focus:ring-2 focus:ring-ring"
+                {...register('mailbox_id', { required: 'Seleziona una casella mittente' })}
+              >
+                <option value="">Seleziona casella...</option>
+                {activeCaselle.map((mb) => (
+                  <option key={mb.id} value={mb.id}>
+                    {mb.fromVbox ? ' ' : ''}{mb.display_name || mb.email_address} ({mb.email_address})
+                  </option>
+                ))}
+              </select>
+              {activeCaselle.some((m) => m.fromVbox) && (
+                <p className="text-xs text-purple-600 flex items-center gap-1">
+                  <Filter className="h-3 w-3" />
+                  Le caselle con sono accessibili tramite Virtual Box
+                </p>
+              )}
+            </>
+          )}
+          {errors.mailbox_id && (
+            <p className="text-xs text-destructive">{errors.mailbox_id.message}</p>
+          )}
+        </div>
+
+        {/* Destinatari A: */}
+        <div className="space-y-1">
+          <div className="flex items-center justify-between">
+            <Label className="text-xs">Destinatari (A:) *</Label>
+            <button
+              type="button"
+              onClick={() => appendTo({ value: '' })}
+              className="text-xs text-primary hover:underline flex items-center gap-0.5"
+            >
+              <Plus className="h-3 w-3" />
+              Aggiungi
+            </button>
+          </div>
+          <div className="space-y-1.5">
+            {toFields.map((field, idx) => (
+              <div key={field.id} className="flex flex-col gap-0.5">
+                <div className="flex gap-1.5">
+                  <Input
+                    type="email"
+                    placeholder="destinatario@pec.it"
+                    className="h-8 text-sm"
+                    {...register(`to_addresses.${idx}.value`, {
+                      required: idx === 0 ? 'Almeno un destinatario e obbligatorio' : false,
+                      pattern: { value: /^[^\s@]+@[^\s@]+\.[^\s@]+$/, message: 'Indirizzo non valido' },
+                    })}
+                  />
+                  {toFields.length > 1 && (
+                    <button
+                      type="button"
+                      onClick={() => removeTo(idx)}
+                      className="p-1 rounded hover:bg-muted text-muted-foreground hover:text-destructive"
+                    >
+                      <X className="h-3.5 w-3.5" />
+                    </button>
+                  )}
+                </div>
+                {errors.to_addresses?.[idx]?.value && (
+                  <p className="text-xs text-destructive">{errors.to_addresses[idx]?.value?.message}</p>
+                )}
+              </div>
+            ))}
+          </div>
+        </div>
+
+        {/* CC */}
+        <div className="space-y-1">
+          {!showCc ? (
+            <button
+              type="button"
+              onClick={() => setShowCc(true)}
+              className="text-xs text-primary hover:underline"
+            >
+              + Aggiungi Cc
+            </button>
+          ) : (
+            <>
+              <div className="flex items-center justify-between">
+                <Label className="text-xs">Copia (Cc:)</Label>
+                <button
+                  type="button"
+                  onClick={() => appendCc({ value: '' })}
+                  className="text-xs text-primary hover:underline flex items-center gap-0.5"
+                >
+                  <Plus className="h-3 w-3" />
+                  Aggiungi
+                </button>
+              </div>
+              {ccFields.map((field, idx) => (
+                <div key={field.id} className="flex flex-col gap-0.5">
+                  <div className="flex gap-1.5">
+                    <Input
+                      type="email"
+                      placeholder="cc@pec.it"
+                      className="h-8 text-sm"
+                      {...register(`cc_addresses.${idx}.value`, {
+                        pattern: { value: /^[^\s@]+@[^\s@]+\.[^\s@]+$/, message: 'Indirizzo non valido' },
+                      })}
+                    />
+                    <button
+                      type="button"
+                      onClick={() => removeCc(idx)}
+                      className="p-1 rounded hover:bg-muted text-muted-foreground hover:text-destructive"
+                    >
+                      <X className="h-3.5 w-3.5" />
+                    </button>
+                  </div>
+                  {errors.cc_addresses?.[idx]?.value && (
+                    <p className="text-xs text-destructive">{errors.cc_addresses[idx]?.value?.message}</p>
+                  )}
+                </div>
+              ))}
+            </>
+          )}
+        </div>
+
+        {/* Oggetto */}
+        <div className="space-y-1">
+          <Label className="text-xs">Oggetto *</Label>
+          <Input
+            placeholder="Oggetto della PEC"
+            className="h-8 text-sm"
+            {...register('subject', { required: "L'oggetto e obbligatorio" })}
+          />
+          {errors.subject && (
+            <p className="text-xs text-destructive">{errors.subject.message}</p>
+          )}
+        </div>
+
+        {/* Corpo */}
+        <div className="space-y-1">
+          <Label className="text-xs">Testo del messaggio</Label>
+          <RichTextEditor
+            value={bodyHtml}
+            onChange={setBodyHtml}
+            placeholder="Scrivi il testo della PEC..."
+            minHeight="160px"
+          />
+        </div>
+
+        {/* Allegati */}
+        <div className="space-y-1.5">
+          <div className="flex items-center justify-between">
+            <Label className="text-xs">Allegati</Label>
+            <span className="text-xs text-muted-foreground">Max 20 MB</span>
+          </div>
+          {attachments.length > 0 && (
+            <div className="space-y-1">
+              {attachments.map((file, idx) => (
+                <div
+                  key={`${file.name}-${file.size}-${idx}`}
+                  className="flex items-center gap-2 px-2.5 py-1.5 bg-muted/50 border rounded-md"
+                >
+                  <Paperclip className="h-3 w-3 text-muted-foreground flex-shrink-0" />
+                  <span className="text-xs flex-1 truncate font-medium" title={file.name}>{file.name}</span>
+                  <span className="text-xs text-muted-foreground whitespace-nowrap">{formatFileSize(file.size)}</span>
+                  <button
+                    type="button"
+                    className="ml-1 rounded p-0.5 text-muted-foreground hover:text-destructive"
+                    onClick={() => removeAttachment(idx)}
+                  >
+                    <X className="h-3 w-3" />
+                  </button>
+                </div>
+              ))}
+            </div>
+          )}
+          <div
+            className="border-2 border-dashed rounded-md p-3 flex flex-col items-center gap-1.5 cursor-pointer hover:border-primary/60 hover:bg-primary/5 transition-colors"
+            onClick={() => fileInputRef.current?.click()}
+            onDragOver={(e) => { e.preventDefault(); e.stopPropagation() }}
+            onDrop={(e) => { e.preventDefault(); handleFileAdd(e.dataTransfer.files) }}
+          >
+            <Upload className="h-5 w-5 text-muted-foreground" />
+            <p className="text-xs text-muted-foreground">Clicca o trascina i file qui</p>
+          </div>
+          <input
+            ref={fileInputRef}
+            type="file"
+            multiple
+            className="hidden"
+            onChange={(e) => handleFileAdd(e.target.files)}
+          />
+        </div>
+      </div>
+
+      {/* Footer azioni */}
+      <div className="px-4 py-3 border-t flex items-center justify-between bg-muted/30">
+        <button
+          type="button"
+          onClick={onClose}
+          className="text-sm text-muted-foreground hover:text-foreground transition-colors"
+        >
+          Annulla
+        </button>
+        <Button
+          type="submit"
+          size="sm"
+          isLoading={sendMutation.isPending}
+          disabled={activeCaselle.length === 0}
+        >
+          <Send className="h-3.5 w-3.5 mr-1.5" />
+          Invia PEC
+          {attachments.length > 0 && (
+            <span className="ml-1.5 bg-primary-foreground/20 text-primary-foreground rounded-full px-1.5 text-xs font-semibold">
+              +{attachments.length}
+            </span>
+          )}
+        </Button>
+      </div>
+    </form>
+  )
+}
+
+// ─── Componente principale flottante ──────────────────────────────────────────
+
+export function ComposeModal() {
+  const { isOpen, mode, replyTo, forwardOf, closeCompose, setMode } = useComposeStore()
+
+  // Chiudi con ESC (solo quando non minimizzato)
+  useEffect(() => {
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === 'Escape' && isOpen && mode !== 'minimized') {
+        closeCompose()
+      }
+    }
+    window.addEventListener('keydown', handler)
+    return () => window.removeEventListener('keydown', handler)
+  }, [isOpen, mode, closeCompose])
+
+  if (!isOpen) return null
+
+  const title = replyTo ? 'Rispondi a PEC' : forwardOf ? 'Inoltra PEC' : 'Nuova PEC'
+  const subtitle = replyTo?.subject || forwardOf?.subject || null
+
+  // Stile inline per il posizionamento (piu' affidabile delle classi Tailwind dinamiche)
+  const containerStyle = (() => {
+    if (mode === 'fullscreen') {
+      return {
+        position: 'fixed' as const,
+        top: '1rem',
+        right: '1rem',
+        bottom: '1rem',
+        left: '1rem',
+      }
+    }
+    if (mode === 'minimized') {
+      return {
+        position: 'fixed' as const,
+        bottom: 0,
+        right: '1.5rem',
+        width: '320px',
+        height: '48px',
+      }
+    }
+    // normal
+    return {
+      position: 'fixed' as const,
+      bottom: 0,
+      right: '1.5rem',
+      width: '560px',
+      height: '580px',
+    }
+  })()
+
+  return (
+    <div
+      className="z-50 flex flex-col bg-background border shadow-2xl rounded-t-xl overflow-hidden transition-all duration-200"
+      style={containerStyle}
+    >
+      {/* Barra del titolo */}
+      <div
+        className="flex items-center justify-between px-4 h-12 flex-shrink-0 bg-primary text-primary-foreground select-none cursor-pointer"
+        onClick={() => {
+          if (mode === 'minimized') setMode('normal')
+        }}
+      >
+        <div className="flex flex-col min-w-0">
+          <span className="text-sm font-semibold truncate leading-tight">{title}</span>
+          {subtitle && mode !== 'normal' && (
+            <span className="text-xs opacity-75 truncate leading-tight">{subtitle}</span>
+          )}
+        </div>
+
+        <div
+          className="flex items-center gap-1 ml-2 flex-shrink-0"
+          onClick={(e) => e.stopPropagation()}
+        >
+          {/* Minimizza */}
+          <button
+            type="button"
+            title={mode === 'minimized' ? 'Espandi' : 'Minimizza'}
+            onClick={() => setMode(mode === 'minimized' ? 'normal' : 'minimized')}
+            className="p-1.5 rounded hover:bg-white/20 transition-colors"
+          >
+            <Minus className="h-3.5 w-3.5" />
+          </button>
+
+          {/* Fullscreen / Ripristina */}
+          {mode !== 'minimized' && (
+            <button
+              type="button"
+              title={mode === 'fullscreen' ? 'Ripristina dimensione' : 'Schermo intero'}
+              onClick={() => setMode(mode === 'fullscreen' ? 'normal' : 'fullscreen')}
+              className="p-1.5 rounded hover:bg-white/20 transition-colors"
+            >
+              {mode === 'fullscreen' ? (
+                <Minimize2 className="h-3.5 w-3.5" />
+              ) : (
+                <Maximize2 className="h-3.5 w-3.5" />
+              )}
+            </button>
+          )}
+
+          {/* Chiudi */}
+          <button
+            type="button"
+            title="Chiudi"
+            onClick={closeCompose}
+            className="p-1.5 rounded hover:bg-white/20 transition-colors"
+          >
+            <X className="h-3.5 w-3.5" />
+          </button>
+        </div>
+      </div>
+
+      {/* Corpo (nascosto quando minimizzato) */}
+      {mode !== 'minimized' && (
+        <div className="flex-1 overflow-hidden flex flex-col">
+          {/*
+            Key basata su replyTo/forwardOf: garantisce che il form venga rimontato
+            (e quindi resettato) ogni volta che si apre per un messaggio diverso.
+          */}
+          <ComposeForm
+            key={`${replyTo?.id ?? 'new'}-${forwardOf?.id ?? 'new'}`}
+            replyTo={replyTo}
+            forwardOf={forwardOf}
+            onClose={closeCompose}
+          />
+        </div>
+      )}
+    </div>
+  )
+}
diff --git a/frontend/src/components/Layout/AppLayout.tsx b/frontend/src/components/Layout/AppLayout.tsx
index 233aa79..be41106 100644
--- a/frontend/src/components/Layout/AppLayout.tsx
+++ b/frontend/src/components/Layout/AppLayout.tsx
@@ -1,6 +1,7 @@
 import { Outlet, Navigate } from 'react-router-dom'
 import { Toaster } from 'react-hot-toast'
 import { Sidebar } from './Sidebar'
+import { ComposeModal } from '@/components/ComposeModal/ComposeModal'
 import { useAuth } from '@/hooks/useAuth'
 import { useWebSocket } from '@/hooks/useWebSocket'
 import { useEffect } from 'react'
@@ -59,6 +60,9 @@ export function AppLayout() {
           },
         }}
       />
+
+      {/* Finestra di composizione PEC flottante (stile Gmail) */}
+      <ComposeModal />
     </div>
   )
 }
diff --git a/frontend/src/pages/Compose/ComposePage.tsx b/frontend/src/pages/Compose/ComposePage.tsx
index a08faa7..f76da4e 100644
--- a/frontend/src/pages/Compose/ComposePage.tsx
+++ b/frontend/src/pages/Compose/ComposePage.tsx
@@ -259,6 +259,7 @@ export function ComposePage() {
       <div className="flex-1 overflow-y-auto">
         <form
           onSubmit={handleSubmit(onSubmit)}
+          noValidate
           className="max-w-4xl mx-auto px-6 py-6 space-y-5"
         >
           {/* Avviso informativo */}
@@ -335,33 +336,39 @@ export function ComposePage() {
             </div>
             <div className="space-y-2">
               {toFields.map((field, idx) => (
-                <div key={field.id} className="flex gap-2">
-                  <Input
-                    type="email"
-                    placeholder="destinatario@pec.it"
-                    {...register(`to_addresses.${idx}.value`, {
-                      required:
-                        idx === 0 ? 'Almeno un destinatario è obbligatorio' : false,
-                    })}
-                  />
-                  {toFields.length > 1 && (
-                    <Button
-                      type="button"
-                      variant="ghost"
-                      size="icon"
-                      onClick={() => removeTo(idx)}
-                    >
-                      <X className="h-4 w-4" />
-                    </Button>
+                <div key={field.id} className="flex flex-col gap-1">
+                  <div className="flex gap-2">
+                    <Input
+                      type="email"
+                      placeholder="destinatario@pec.it"
+                      {...register(`to_addresses.${idx}.value`, {
+                        required:
+                          idx === 0 ? 'Almeno un destinatario è obbligatorio' : false,
+                        pattern: {
+                          value: /^[^\s@]+@[^\s@]+\.[^\s@]+$/,
+                          message: 'Inserisci un indirizzo email valido',
+                        },
+                      })}
+                    />
+                    {toFields.length > 1 && (
+                      <Button
+                        type="button"
+                        variant="ghost"
+                        size="icon"
+                        onClick={() => removeTo(idx)}
+                      >
+                        <X className="h-4 w-4" />
+                      </Button>
+                    )}
+                  </div>
+                  {errors.to_addresses?.[idx]?.value && (
+                    <p className="text-xs text-destructive">
+                      {errors.to_addresses[idx]?.value?.message}
+                    </p>
                   )}
                 </div>
               ))}
             </div>
-            {errors.to_addresses?.[0]?.value && (
-              <p className="text-xs text-destructive">
-                {errors.to_addresses[0].value.message}
-              </p>
-            )}
           </div>
 
           {/* CC */}
@@ -389,20 +396,32 @@ export function ComposePage() {
                   </Button>
                 </div>
                 {ccFields.map((field, idx) => (
-                  <div key={field.id} className="flex gap-2">
-                    <Input
-                      type="email"
-                      placeholder="cc@pec.it"
-                      {...register(`cc_addresses.${idx}.value`)}
-                    />
-                    <Button
-                      type="button"
-                      variant="ghost"
-                      size="icon"
-                      onClick={() => removeCc(idx)}
-                    >
-                      <X className="h-4 w-4" />
-                    </Button>
+                  <div key={field.id} className="flex flex-col gap-1">
+                    <div className="flex gap-2">
+                      <Input
+                        type="email"
+                        placeholder="cc@pec.it"
+                        {...register(`cc_addresses.${idx}.value`, {
+                          pattern: {
+                            value: /^[^\s@]+@[^\s@]+\.[^\s@]+$/,
+                            message: 'Inserisci un indirizzo email valido',
+                          },
+                        })}
+                      />
+                      <Button
+                        type="button"
+                        variant="ghost"
+                        size="icon"
+                        onClick={() => removeCc(idx)}
+                      >
+                        <X className="h-4 w-4" />
+                      </Button>
+                    </div>
+                    {errors.cc_addresses?.[idx]?.value && (
+                      <p className="text-xs text-destructive">
+                        {errors.cc_addresses[idx]?.value?.message}
+                      </p>
+                    )}
                   </div>
                 ))}
               </>
diff --git a/frontend/src/pages/MessageDetail/MessageDetailPage.tsx b/frontend/src/pages/MessageDetail/MessageDetailPage.tsx
index 170cc35..88f2b68 100644
--- a/frontend/src/pages/MessageDetail/MessageDetailPage.tsx
+++ b/frontend/src/pages/MessageDetail/MessageDetailPage.tsx
@@ -37,6 +37,7 @@ import { deadlinesApi } from '@/api/deadlines.api'
 import { formatDate, formatBytes } from '@/lib/utils'
 import { getErrorMessage } from '@/api/client'
 import apiClient from '@/api/client'
+import { useComposeStore } from '@/store/compose.store'
 
 // ─── Thread section (Feature 3) ──────────────────────────────────────────────
 
@@ -100,13 +101,23 @@ interface AttachmentPreviewProps {
 }
 
 function AttachmentPreviewModal({ messageId, attachmentId, filename, contentType, onClose }: AttachmentPreviewProps) {
-  const { data, isLoading } = useQuery({
-    queryKey: ['attachment-preview', messageId, attachmentId],
-    queryFn: () => messagesApi.getAttachmentPreviewUrl(messageId, attachmentId),
+  const isPreviewable = contentType.startsWith('image/') || contentType === 'application/pdf'
+
+  const { data: blobUrl, isLoading, isError } = useQuery({
+    queryKey: ['attachment-inline', messageId, attachmentId],
+    queryFn: async () => {
+      const response = await apiClient.get(
+        `/messages/${messageId}/attachments/${attachmentId}/inline`,
+        { responseType: 'blob' },
+      )
+      return window.URL.createObjectURL(new Blob([response.data], { type: contentType }))
+    },
+    enabled: isPreviewable,
+    staleTime: 5 * 60 * 1000,
   })
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/80">
+    <div className="fixed inset-0 z-[60] flex items-center justify-center bg-black/80">
       <div className="relative bg-background rounded-xl shadow-2xl w-full max-w-4xl max-h-[90vh] flex flex-col">
         <div className="flex items-center justify-between px-4 py-3 border-b">
           <span className="font-medium truncate">{filename}</span>
@@ -118,24 +129,27 @@ function AttachmentPreviewModal({ messageId, attachmentId, filename, contentType
           {isLoading && (
             <div className="h-8 w-8 animate-spin rounded-full border-4 border-primary border-t-transparent" />
           )}
-          {!isLoading && data && (
+          {isError && (
+            <div className="text-center text-muted-foreground">
+              <Eye className="h-12 w-12 mx-auto mb-3 opacity-30" />
+              <p>Errore nel caricamento del file.</p>
+            </div>
+          )}
+          {!isLoading && !isError && blobUrl && (
             <>
-              {data.previewable && data.url ? (
-                <>
-                  {contentType.startsWith('image/') ? (
-                    <img src={data.url} alt={filename} className="max-w-full max-h-full object-contain" />
-                  ) : contentType === 'application/pdf' ? (
-                    <iframe src={data.url} className="w-full h-[70vh]" title={filename} />
-                  ) : null}
-                </>
-              ) : (
-                <div className="text-center text-muted-foreground">
-                  <Eye className="h-12 w-12 mx-auto mb-3 opacity-30" />
-                  <p>Anteprima non disponibile per questo tipo di file.</p>
-                </div>
-              )}
+              {contentType.startsWith('image/') ? (
+                <img src={blobUrl} alt={filename} className="max-w-full max-h-full object-contain" />
+              ) : contentType === 'application/pdf' ? (
+                <iframe src={blobUrl} className="w-full h-[70vh]" title={filename} />
+              ) : null}
             </>
           )}
+          {!isLoading && !isError && !isPreviewable && (
+            <div className="text-center text-muted-foreground">
+              <Eye className="h-12 w-12 mx-auto mb-3 opacity-30" />
+              <p>Anteprima non disponibile per questo tipo di file.</p>
+            </div>
+          )}
         </div>
       </div>
     </div>
@@ -148,6 +162,7 @@ export function MessageDetailPage() {
   const { id } = useParams<{ id: string }>()
   const navigate = useNavigate()
   const queryClient = useQueryClient()
+  const openCompose = useComposeStore((s) => s.openCompose)
 
   const [showTagSelector, setShowTagSelector] = useState(false)
   const [isDownloadingPackage, setIsDownloadingPackage] = useState(false)
@@ -161,6 +176,12 @@ export function MessageDetailPage() {
   // Feature 7: Preview allegati
   const [previewAtt, setPreviewAtt] = useState<{ id: string; filename: string; contentType: string } | null>(null)
 
+  // Modal stampa con allegati
+  const [showPrintModal, setShowPrintModal] = useState(false)
+  const [printBody, setPrintBody] = useState(true)
+  const [printAttIds, setPrintAttIds] = useState<Set<string>>(new Set())
+  const [printModalPreviewAtt, setPrintModalPreviewAtt] = useState<{ id: string; filename: string; contentType: string } | null>(null)
+
   // Carica messaggio
   const {
     data: message,
@@ -254,6 +275,79 @@ export function MessageDetailPage() {
     onError: (error) => toast.error(getErrorMessage(error)),
   })
 
+  // Stampa diretta (senza modal)
+  const handlePrintDirect = async () => {
+    if (!message) return
+    setIsPrinting(true)
+    try {
+      const response = await apiClient.get(`/messages/${message.id}/print`, { responseType: 'blob' })
+      const html = await response.data.text()
+      const w = window.open('', '_blank')
+      if (w) {
+        w.document.write(html)
+        w.document.close()
+        setTimeout(() => w.print(), 500)
+      }
+    } catch (e) {
+      toast.error('Errore apertura stampa')
+    } finally {
+      setIsPrinting(false)
+    }
+  }
+
+  // Stampa con selezione dal modal
+  const handlePrintFromModal = async () => {
+    if (!message) return
+    setShowPrintModal(false)
+    setIsPrinting(true)
+    try {
+      // 1. Stampa corpo email se selezionato
+      if (printBody) {
+        const response = await apiClient.get(`/messages/${message.id}/print`, { responseType: 'blob' })
+        const html = await response.data.text()
+        const w = window.open('', '_blank')
+        if (w) {
+          w.document.write(html)
+          w.document.close()
+          setTimeout(() => w.print(), 500)
+        }
+      }
+
+      // 2. Per ogni allegato selezionato, apre in nuova finestra tramite blob URL
+      const selectedAtts = attachments.filter((a) => printAttIds.has(a.id))
+      for (const att of selectedAtts) {
+        const isPrintable = att.content_type?.startsWith('image/') || att.content_type === 'application/pdf'
+        if (!isPrintable) {
+          toast(`Allegato "${att.filename}" non stampabile direttamente: scaricarlo e stamparlo manualmente.`, { icon: 'i' })
+          continue
+        }
+        try {
+          const resp = await apiClient.get(
+            `/messages/${message.id}/attachments/${att.id}/inline`,
+            { responseType: 'blob' },
+          )
+          const blobUrl = window.URL.createObjectURL(new Blob([resp.data], { type: att.content_type || 'application/octet-stream' }))
+          const attWin = window.open(blobUrl, '_blank')
+          if (attWin) {
+            setTimeout(() => {
+              try { attWin.print() } catch (_) { /* ignora */ }
+              window.URL.revokeObjectURL(blobUrl)
+            }, 1500)
+          } else {
+            window.URL.revokeObjectURL(blobUrl)
+            toast.error(`Impossibile aprire "${att.filename}": controlla che i popup non siano bloccati.`)
+          }
+        } catch (_) {
+          toast.error(`Errore apertura allegato "${att.filename}"`)
+        }
+      }
+    } catch (e) {
+      toast.error('Errore apertura stampa')
+    } finally {
+      setIsPrinting(false)
+    }
+  }
+
   // Download allegato autenticato
   const handleDownloadAttachment = async (att: { id: string; filename: string }) => {
     try {
@@ -444,11 +538,7 @@ export function MessageDetailPage() {
             <Button
               variant="outline"
               size="sm"
-              onClick={() =>
-                navigate('/compose', {
-                  state: { replyTo: message },
-                })
-              }
+              onClick={() => openCompose({ replyTo: message })}
             >
               <Reply className="h-4 w-4 mr-1" />
               Rispondi
@@ -460,11 +550,7 @@ export function MessageDetailPage() {
             <Button
               variant="outline"
               size="sm"
-              onClick={() =>
-                navigate('/compose', {
-                  state: { forwardOf: message },
-                })
-              }
+              onClick={() => openCompose({ forwardOf: message })}
             >
               <Forward className="h-4 w-4 mr-1" />
               Inoltra
@@ -492,22 +578,17 @@ export function MessageDetailPage() {
             variant="outline"
             size="sm"
             isLoading={isPrinting}
-            onClick={async () => {
+            onClick={() => {
               if (!message) return
-              setIsPrinting(true)
-              try {
-                const response = await apiClient.get(`/messages/${message.id}/print`, { responseType: 'blob' })
-                const html = await response.data.text()
-                const w = window.open('', '_blank')
-                if (w) {
-                  w.document.write(html)
-                  w.document.close()
-                  setTimeout(() => w.print(), 500)
-                }
-              } catch (e) {
-                toast.error('Errore apertura stampa')
-              } finally {
-                setIsPrinting(false)
+              if (attachments.length > 0) {
+                // Apre modal di selezione stampa
+                setPrintBody(true)
+                setPrintAttIds(new Set())
+                setPrintModalPreviewAtt(null)
+                setShowPrintModal(true)
+              } else {
+                // Nessun allegato: stampa direttamente come prima
+                handlePrintDirect()
               }
             }}
             title="Stampa / Salva come PDF"
@@ -851,6 +932,132 @@ export function MessageDetailPage() {
         />
       )}
 
+      {/* Modal stampa con selezione allegati */}
+      {showPrintModal && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50">
+          <div className="bg-background rounded-xl shadow-2xl w-full max-w-lg">
+            {/* Header */}
+            <div className="flex items-center justify-between px-5 py-4 border-b">
+              <h3 className="text-lg font-semibold flex items-center gap-2">
+                <Printer className="h-5 w-5 text-primary" />
+                Stampa messaggio
+              </h3>
+              <button
+                onClick={() => setShowPrintModal(false)}
+                className="p-1 rounded hover:bg-muted"
+              >
+                <X className="h-5 w-5" />
+              </button>
+            </div>
+
+            {/* Body */}
+            <div className="px-5 py-4 space-y-4">
+              <p className="text-sm text-muted-foreground">Seleziona cosa includere nella stampa:</p>
+
+              {/* Checkbox corpo email */}
+              <label className="flex items-center gap-3 cursor-pointer group">
+                <input
+                  type="checkbox"
+                  checked={printBody}
+                  onChange={(e) => setPrintBody(e.target.checked)}
+                  className="h-4 w-4 rounded border-gray-300 accent-primary"
+                />
+                <div className="flex-1">
+                  <span className="text-sm font-medium">Corpo della email</span>
+                  <p className="text-xs text-muted-foreground">Intestazione, mittente, destinatari e testo del messaggio</p>
+                </div>
+              </label>
+
+              {/* Separatore */}
+              <div className="border-t pt-3 space-y-1">
+                <p className="text-xs font-semibold text-muted-foreground uppercase tracking-wide flex items-center gap-1.5">
+                  <Paperclip className="h-3.5 w-3.5" />
+                  Allegati ({attachments.length})
+                </p>
+                <div className="space-y-2 mt-2 max-h-60 overflow-y-auto pr-1">
+                  {attachments.map((att) => {
+                    const isPreviewable = att.content_type?.startsWith('image/') || att.content_type === 'application/pdf'
+                    const isPrintable = isPreviewable
+                    return (
+                      <div
+                        key={att.id}
+                        className="flex items-center gap-3 rounded-lg border bg-muted/30 px-3 py-2"
+                      >
+                        <input
+                          type="checkbox"
+                          checked={printAttIds.has(att.id)}
+                          onChange={(e) => {
+                            setPrintAttIds((prev) => {
+                              const next = new Set(prev)
+                              if (e.target.checked) next.add(att.id)
+                              else next.delete(att.id)
+                              return next
+                            })
+                          }}
+                          className="h-4 w-4 rounded border-gray-300 accent-primary flex-shrink-0"
+                        />
+                        <div className="flex-1 min-w-0">
+                          <p className="text-sm font-medium truncate">{att.filename}</p>
+                          <p className="text-xs text-muted-foreground">
+                            {att.content_type || 'Tipo sconosciuto'} &bull; {formatBytes(att.size_bytes)}
+                            {!isPrintable && (
+                              <span className="ml-1.5 text-amber-600">(stampa non diretta)</span>
+                            )}
+                          </p>
+                        </div>
+                        {/* Pulsante anteprima all'interno del modal */}
+                        {isPreviewable && (
+                          <button
+                            type="button"
+                            onClick={() => setPrintModalPreviewAtt({ id: att.id, filename: att.filename, contentType: att.content_type || '' })}
+                            className="p-1.5 rounded hover:bg-muted text-muted-foreground hover:text-primary flex-shrink-0"
+                            title="Visualizza allegato"
+                          >
+                            <Eye className="h-4 w-4" />
+                          </button>
+                        )}
+                      </div>
+                    )
+                  })}
+                </div>
+              </div>
+
+              {/* Nota per allegati non stampabili */}
+              {attachments.some((a) => !a.content_type?.startsWith('image/') && a.content_type !== 'application/pdf') && (
+                <p className="text-xs text-amber-700 bg-amber-50 border border-amber-200 rounded-md px-3 py-2">
+                  Gli allegati contrassegnati con "stampa non diretta" (es. .eml, .xml) non possono essere aperti direttamente dal browser. Scaricali e stampali manualmente.
+                </p>
+              )}
+            </div>
+
+            {/* Footer */}
+            <div className="flex justify-end gap-3 px-5 py-4 border-t">
+              <Button variant="outline" onClick={() => setShowPrintModal(false)}>
+                Annulla
+              </Button>
+              <Button
+                onClick={handlePrintFromModal}
+                disabled={!printBody && printAttIds.size === 0}
+              >
+                <Printer className="h-4 w-4 mr-1" />
+                Stampa
+              </Button>
+            </div>
+          </div>
+
+          {/* Anteprima allegato aperta dall'interno del modal (z-index superiore) */}
+          {printModalPreviewAtt && (
+            <AttachmentPreviewModal
+              messageId={message.id}
+              attachmentId={printModalPreviewAtt.id}
+              filename={printModalPreviewAtt.filename}
+              contentType={printModalPreviewAtt.contentType}
+              onClose={() => setPrintModalPreviewAtt(null)}
+            />
+          )}
+        </div>
+      )}
+
       {/* Dialog gestione tag */}
       {showTagSelector && (
         <TagSelector
diff --git a/frontend/src/store/compose.store.ts b/frontend/src/store/compose.store.ts
new file mode 100644
index 0000000..ba58b19
--- /dev/null
+++ b/frontend/src/store/compose.store.ts
@@ -0,0 +1,44 @@
+/**
+ * Compose Store (Zustand) – stato globale della finestra di composizione.
+ */
+
+import { create } from 'zustand'
+import type { MessageResponse } from '@/types/api.types'
+
+type ComposeMode = 'normal' | 'minimized' | 'fullscreen'
+
+interface ComposeState {
+  isOpen: boolean
+  mode: ComposeMode
+  replyTo: MessageResponse | null
+  forwardOf: MessageResponse | null
+
+  openCompose: (opts?: { replyTo?: MessageResponse; forwardOf?: MessageResponse }) => void
+  closeCompose: () => void
+  setMode: (mode: ComposeMode) => void
+}
+
+export const useComposeStore = create<ComposeState>()((set) => ({
+  isOpen: false,
+  mode: 'normal',
+  replyTo: null,
+  forwardOf: null,
+
+  openCompose: (opts) =>
+    set({
+      isOpen: true,
+      mode: 'normal',
+      replyTo: opts?.replyTo ?? null,
+      forwardOf: opts?.forwardOf ?? null,
+    }),
+
+  closeCompose: () =>
+    set({
+      isOpen: false,
+      mode: 'normal',
+      replyTo: null,
+      forwardOf: null,
+    }),
+
+  setMode: (mode) => set({ mode }),
+}))