feat: split a pasted address list into recipient chips

Pasting a list of addresses into To/Cc/Bcc now creates one chip per
address instead of dropping the whole blob in as a single invalid chip.
A paste is split only when it actually contains a separator; a lone
address falls through to normal editing.

- Separators: commas, semicolons, and any whitespace/newline - covers
  comma/space dumps, spreadsheet columns and Outlook-style `;` lists.
- Display names are preserved: `Name <email>`, a fully-quoted
  `"Name <email>"` entry, and `"Doe, John" <email>` (comma inside a
  quoted name) each stay a single chip with the name intact.
- Bare-address runs split per address; a `<addr>` token is unwrapped;
  tokens that aren't valid addresses are left behind in the input for
  the user to fix rather than becoming junk chips.
- Deduped case-insensitively within the paste and against existing chips.

Implemented as splitPastedRecipients in email-composer-utils, layered on
the shared quote/angle-aware splitter: splitRecipients gains an optional
`separators` argument so the composer/mailto serialization boundary
(comma-only) and the paste path (`,;\n\r`) share one implementation.
Wired into the recipient chip input's onPaste handler (To/Cc/Bcc).

components/email/__tests__/recipient-chip-drag.test.tsx

@@ -160,6 +160,7 @@ vi.mock('@/lib/plugin-hooks', () => ({
 vi.mock('@/lib/email-sanitization', () => ({
   sanitizeSignatureHtml: (v: string) => v,
   sanitizeEmailHtml: (v: string) => v,
+  parseHtmlSafely: (html: string) => new DOMParser().parseFromString(html, 'text/html'),
 }));
 
 vi.mock('@/lib/reply-identity', () => ({ resolveReplyFrom: () => null }));

components/email/__tests__/recipient-paste.test.tsx

@@ -0,0 +1,317 @@
+import { render, screen } from '@testing-library/react';
+import { fireEvent } from '@testing-library/dom';
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import React from 'react';
+import { EmailComposer } from '../email-composer';
+
+// ─── Heavy component mocks (mirrors recipient-chip-drag.test.tsx) ──────────────
+
+vi.mock('@/components/email/rich-text-editor', () => ({
+  RichTextEditor: ({ onChange }: { onChange?: (html: string) => void }) => (
+    React.createElement('div', { 'data-testid': 'rich-text-editor', onClick: () => onChange?.('') })
+  ),
+}));
+
+vi.mock('@/components/plugins/plugin-slot', () => ({ PluginSlot: () => null }));
+vi.mock('@/components/identity/sub-address-helper', () => ({ SubAddressHelper: () => null }));
+vi.mock('@/components/templates/template-picker', () => ({ TemplatePicker: () => null }));
+vi.mock('@/components/templates/template-form', () => ({ TemplateForm: () => null }));
+vi.mock('@/components/files/file-preview-modal', () => ({ FilePreviewModal: () => null }));
+vi.mock('@/hooks/use-focus-trap', () => ({
+  useFocusTrap: () => ({ ref: { current: null } }),
+}));
+vi.mock('@/hooks/use-pro-multi-account-identities', () => ({
+  useProMultiAccountIdentities: () => ({ enabled: false, groups: [], allIdentities: [] }),
+  stripCrossAccountIdentityPrefix: (id: string) => ({ localAccountId: null, rawId: id }),
+}));
+
+// ─── Store mocks ──────────────────────────────────────────────────────────────
+
+vi.mock('@/stores/auth-store', () => {
+  const state = {
+    client: null,
+    identities: [],
+    primaryIdentity: null,
+    isAuthenticated: false,
+    isDemoMode: false,
+    activeAccountId: null,
+    connectionLost: false,
+    getClientForAccount: () => undefined,
+    getAllConnectedClients: () => new Map(),
+    syncIdentities: () => {},
+    refreshIdentities: async () => {},
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useAuthStore: hook };
+});
+
+vi.mock('@/stores/identity-store', () => {
+  const state = { identities: [], defaultIdentityId: null };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useIdentityStore: hook };
+});
+
+vi.mock('@/stores/account-store', () => {
+  const state = { accounts: [], getAccountById: () => undefined };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useAccountStore: hook };
+});
+
+vi.mock('@/stores/smime-store', () => {
+  const state = {
+    certs: [],
+    signingEnabled: false,
+    encryptionEnabled: false,
+    defaultSigningCertId: null,
+    defaultEncryptionCertId: null,
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useSmimeStore: hook };
+});
+
+vi.mock('@/stores/email-store', () => {
+  const state = {
+    draftSaveEnabled: false,
+    sendRawEmail: async () => ({ sent: true }),
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useEmailStore: hook };
+});
+
+vi.mock('@/stores/settings-store', () => {
+  const state = {
+    timeFormat: '24h',
+    plainTextMode: false,
+    subAddressDelimiter: '+',
+    autoSelectReplyIdentity: true,
+    attachmentReminderEnabled: false,
+    attachmentReminderKeywords: [],
+    sendDelaySeconds: 0,
+    signaturePosition: 'above_quote',
+    signatureSeparatorEnabled: false,
+    requestReadReceiptDefault: false,
+    addTrustedSender: () => {},
+    trustedSendersAddressBook: null,
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useSettingsStore: hook };
+});
+
+vi.mock('@/stores/contact-store', () => {
+  const state = {
+    contacts: [],
+    getAutocomplete: async () => [],
+    addToTrustedSendersBook: async () => {},
+  };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useContactStore: hook };
+});
+
+vi.mock('@/stores/template-store', () => {
+  const state = { templates: [], addTemplate: async () => {} };
+  const hook = (sel?: (s: typeof state) => unknown) =>
+    typeof sel === 'function' ? sel(state) : state;
+  hook.getState = () => state;
+  hook.setState = (p: Partial<typeof state>) => Object.assign(state, p);
+  return { useTemplateStore: hook };
+});
+
+// ─── Misc dependency mocks ────────────────────────────────────────────────────
+
+vi.mock('@/stores/toast-store', () => ({
+  toast: { info: () => {}, error: () => {}, success: () => {} },
+}));
+
+vi.mock('@/lib/plugin-hooks', () => ({
+  emailHooks: {
+    onComposerOpen: { call: async () => [] },
+    onRecipientChange: { call: async () => [] },
+    getRecipientSuggestions: { call: async () => [] },
+    onSend: { call: async () => [] },
+    beforeSend: { call: async () => [] },
+  },
+  contactHooks: {
+    search: { call: async () => [] },
+  },
+}));
+
+vi.mock('@/lib/email-sanitization', () => ({
+  sanitizeSignatureHtml: (v: string) => v,
+  sanitizeEmailHtml: (v: string) => v,
+  parseHtmlSafely: (html: string) => new DOMParser().parseFromString(html, 'text/html'),
+}));
+
+vi.mock('@/lib/reply-identity', () => ({ resolveReplyFrom: () => null }));
+vi.mock('@/lib/email-threading', () => ({
+  computeReplyThreadingHeaders: () => ({ inReplyTo: [], references: [] }),
+}));
+vi.mock('@/lib/signature-utils', () => ({
+  appendPlainTextSignature: (body: string) => body,
+  getPlainTextSignature: () => '',
+}));
+vi.mock('@/lib/sub-addressing', () => ({ generateSubAddress: () => '' }));
+vi.mock('@/lib/smime/smime-sign', () => ({ smimeSign: async () => null }));
+vi.mock('@/lib/smime/smime-encrypt', () => ({ smimeEncrypt: async () => null }));
+vi.mock('@/lib/smime/mime-builder', () => ({
+  buildMimeMessage: () => null,
+  wrapCmsAsSmimeMessage: () => null,
+}));
+vi.mock('@/lib/debug', () => ({ debug: () => {} }));
+vi.mock('@/components/email/quoted-html', () => ({
+  buildQuotedHtmlBlock: () => '',
+  serializeEditorContent: () => '',
+}));
+vi.mock('@/lib/template-utils', () => ({ substitutePlaceholders: (s: string) => s }));
+
+// ─── Shared test data ─────────────────────────────────────────────────────────
+
+const EMPTY_DATA = {
+  to: '',
+  cc: '',
+  bcc: '',
+  subject: '',
+  body: '',
+  showCc: true,
+  showBcc: true,
+  selectedIdentityId: null,
+  subAddressTag: '',
+  mode: 'compose' as const,
+  draftId: null,
+};
+
+/** next-intl is mocked to return the key, so the To placeholder is "to_placeholder". */
+const toInput = () => screen.getByPlaceholderText('to_placeholder') as HTMLInputElement;
+const ccInput = () => screen.getByPlaceholderText('cc_placeholder') as HTMLInputElement;
+
+const paste = (input: HTMLElement, text: string) =>
+  fireEvent.paste(input, { clipboardData: { getData: () => text } });
+
+// ─── Tests ────────────────────────────────────────────────────────────────────
+
+describe('RecipientChipInput paste', () => {
+  beforeEach(() => { vi.clearAllMocks(); });
+
+  it('splits a pasted list (comma / semicolon / whitespace) into one chip per address', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput(); // capture once — placeholder disappears once chips exist
+    paste(input, 'a@x.com b@y.com; c@z.com');
+
+    expect(screen.getByText('a@x.com')).toBeInTheDocument();
+    expect(screen.getByText('b@y.com')).toBeInTheDocument();
+    expect(screen.getByText('c@z.com')).toBeInTheDocument();
+    // all consumed → input cleared
+    expect(input.value).toBe('');
+  });
+
+  it('chips the valid addresses and leaves invalid text in the input', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput();
+    paste(input, 'foo bar a@x.com');
+
+    expect(screen.getByText('a@x.com')).toBeInTheDocument();
+    expect(input.value).toBe('foo bar');
+  });
+
+  it('does not pre-empt a single-address paste (no delimiter → normal editing)', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    paste(toInput(), 'single@x.com');
+
+    // The handler bailed out, so no chip was created from the single token.
+    expect(screen.queryByText('single@x.com')).not.toBeInTheDocument();
+  });
+
+  it('keeps display names from a fully-quoted "Name <email>" list', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput();
+    paste(input, '"Alice Smith <alice@x.com>", "Alex Smith <alex@x.com>"');
+
+    // Chips render as "Name (email)" when a display name is present.
+    expect(screen.getByText('Alice Smith (alice@x.com)')).toBeInTheDocument();
+    expect(screen.getByText('Alex Smith (alex@x.com)')).toBeInTheDocument();
+    expect(input.value).toBe('');
+  });
+
+  it('keeps a `Name <email>` pair as a single named chip', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput();
+    paste(input, 'John Doe <j@x.com>, jane@y.com');
+
+    expect(screen.getByText('John Doe (j@x.com)')).toBeInTheDocument();
+    expect(screen.getByText('jane@y.com')).toBeInTheDocument();
+    expect(input.value).toBe('');
+  });
+
+  it('keeps a comma inside a quoted display name intact', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput();
+    paste(input, '"Doe, John" <j@x.com>; bob@z.com');
+
+    expect(screen.getByText('Doe, John (j@x.com)')).toBeInTheDocument();
+    expect(screen.getByText('bob@z.com')).toBeInTheDocument();
+    expect(input.value).toBe('');
+  });
+
+  it('splits a newline-separated block (e.g. a spreadsheet column)', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput();
+    paste(input, 'a@x.com\nb@y.com\nc@z.com');
+
+    expect(screen.getByText('a@x.com')).toBeInTheDocument();
+    expect(screen.getByText('b@y.com')).toBeInTheDocument();
+    expect(screen.getByText('c@z.com')).toBeInTheDocument();
+    expect(input.value).toBe('');
+  });
+
+  it('dedupes case-insensitively within the paste and against existing chips', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput(); // DOM node persists across pastes (placeholder just clears)
+    paste(input, 'a@x.com, A@X.com, b@y.com'); // within-paste dup collapses
+    paste(input, 'A@X.COM, c@z.com'); // dup of an existing chip is dropped
+
+    expect(screen.getByText('b@y.com')).toBeInTheDocument();
+    expect(screen.getByText('c@z.com')).toBeInTheDocument();
+    // a@x.com appears exactly once despite three case variants across two pastes.
+    expect(screen.getAllByText('a@x.com')).toHaveLength(1);
+    expect(screen.queryByText('A@X.COM')).not.toBeInTheDocument();
+    expect(input.value).toBe('');
+  });
+
+  it('chips the valid (named) entries and leaves a non-address token behind', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    const input = toInput();
+    paste(input, '"VIP" <vip@x.com>, not-an-email, b@y.com');
+
+    expect(screen.getByText('VIP (vip@x.com)')).toBeInTheDocument();
+    expect(screen.getByText('b@y.com')).toBeInTheDocument();
+    expect(input.value).toBe('not-an-email');
+  });
+
+  it('works on the Cc field (shared handler)', () => {
+    render(<EmailComposer initialData={EMPTY_DATA} />);
+    paste(ccInput(), 'x@a.com; y@b.com');
+
+    expect(screen.getByText('x@a.com')).toBeInTheDocument();
+    expect(screen.getByText('y@b.com')).toBeInTheDocument();
+  });
+});

components/email/email-composer.tsx

@@ -49,6 +49,7 @@ import {
   parseRecipient,
   parseRecipientList,
   formatRecipientList,
+  splitPastedRecipients,
   type Recipient,
 } from "@/lib/email-composer-utils";
 import { RichTextEditor } from "@/components/email/rich-text-editor";
@@ -2919,6 +2920,20 @@ function RecipientChipInput({
     }
   };
 
+  // Pasting a list of addresses (comma/semicolon/whitespace separated) splits
+  // into one chip per valid address; anything that isn't a valid address is
+  // left in the input for the user to fix. A single address with no separator
+  // falls through to the browser's normal paste so it stays editable.
+  const handlePaste = (e: React.ClipboardEvent<HTMLInputElement>) => {
+    const text = e.clipboardData.getData('text');
+    if (!/[\s,;]/.test(text.trim())) return;
+    const { valid, invalid } = splitPastedRecipients(text, chips.map(c => c.email));
+    if (valid.length === 0) return;
+    e.preventDefault();
+    onChipsChange([...chips, ...valid]);
+    onInputChange([inputText.trim(), invalid.join(' ')].filter(Boolean).join(' '));
+  };
+
   const handleKeyDown = (e: React.KeyboardEvent) => {
     if (activeAutoField === field && autocompleteResults.length > 0) {
       if (e.key === 'ArrowDown' || e.key === 'ArrowUp' || e.key === 'Escape' ||
@@ -3113,6 +3128,7 @@ function RecipientChipInput({
             value={inputText}
             onChange={handleInputChange}
             onKeyDown={handleKeyDown}
+            onPaste={handlePaste}
             onBlur={handleBlur}
             className="flex-1 min-w-[120px] border-0 outline-none h-7 text-sm bg-transparent text-foreground placeholder:text-muted-foreground"
             role="combobox"

lib/__tests__/email-composer-utils.test.ts

@@ -9,6 +9,7 @@ import {
   parseRecipient,
   parseRecipientList,
   formatRecipientList,
+  splitPastedRecipients,
 } from "../email-composer-utils";
 
 describe("plainTextToComposerBody", () => {
@@ -150,6 +151,16 @@ describe("splitRecipients", () => {
   it("returns an empty array for an empty string", () => {
     expect(splitRecipients("")).toEqual([]);
   });
+
+  it("only splits on the given separators (default comma keeps semicolons/newlines literal)", () => {
+    expect(splitRecipients("a@x.com; b@y.com")).toEqual(["a@x.com; b@y.com"]);
+  });
+
+  it("splits on a wider separator set while keeping quotes/angles literal", () => {
+    expect(
+      splitRecipients('"Doo, John" <john@doo.org>; a@x.com\nb@y.com', ',;\n\r'),
+    ).toEqual(['"Doo, John" <john@doo.org>', "a@x.com", "b@y.com"]);
+  });
 });
 
 describe("formatRecipient / parseRecipient", () => {
@@ -198,3 +209,68 @@ describe("parseRecipientList / formatRecipientList", () => {
     expect(parseRecipientList("")).toEqual([]);
   });
 });
+
+describe("splitPastedRecipients", () => {
+  it("splits on commas, semicolons and whitespace (incl. newline/tab)", () => {
+    const { valid, invalid } = splitPastedRecipients(
+      "a@x.com, b@y.com; c@z.com\nd@w.com\te@v.com f@u.com",
+    );
+    expect(valid.map((r) => r.email)).toEqual([
+      "a@x.com", "b@y.com", "c@z.com", "d@w.com", "e@v.com", "f@u.com",
+    ]);
+    expect(invalid).toEqual([]);
+  });
+
+  it("collapses runs of mixed separators and drops empties", () => {
+    const { valid } = splitPastedRecipients("  a@x.com ,;  , b@y.com  ");
+    expect(valid.map((r) => r.email)).toEqual(["a@x.com", "b@y.com"]);
+  });
+
+  it("partitions invalid tokens into `invalid`, keeping valid as chips", () => {
+    const { valid, invalid } = splitPastedRecipients("a@x.com not-an-email b@y.com");
+    expect(valid.map((r) => r.email)).toEqual(["a@x.com", "b@y.com"]);
+    expect(invalid).toEqual(["not-an-email"]);
+  });
+
+  it("unwraps an angle-bracketed token before validating", () => {
+    const { valid } = splitPastedRecipients("<a@x.com>");
+    expect(valid).toEqual([{ email: "a@x.com" }]);
+  });
+
+  it("keeps a `Name <email>` pair as a single chip with its display name", () => {
+    const { valid, invalid } = splitPastedRecipients("John Doe <j@x.com>");
+    expect(valid).toEqual([{ name: "John Doe", email: "j@x.com" }]);
+    expect(invalid).toEqual([]);
+  });
+
+  it("keeps a fully-quoted `\"Name <email>\"` entry with its display name", () => {
+    const { valid, invalid } = splitPastedRecipients(
+      '"Alice Smith <alice@x.com>", "Alex Smith <alex@x.com>"',
+    );
+    expect(valid).toEqual([
+      { name: "Alice Smith", email: "alice@x.com" },
+      { name: "Alex Smith", email: "alex@x.com" },
+    ]);
+    expect(invalid).toEqual([]);
+  });
+
+  it("keeps a comma inside a quoted display name intact", () => {
+    const { valid } = splitPastedRecipients('"Doe, John" <j@x.com>; bob@z.com');
+    expect(valid).toEqual([
+      { name: "Doe, John", email: "j@x.com" },
+      { email: "bob@z.com" },
+    ]);
+  });
+
+  it("dedupes case-insensitively within the paste and against existing emails", () => {
+    const { valid } = splitPastedRecipients(
+      "a@x.com A@X.com b@y.com c@z.com",
+      ["B@Y.com"],
+    );
+    expect(valid.map((r) => r.email)).toEqual(["a@x.com", "c@z.com"]);
+  });
+
+  it("returns empty arrays for blank input", () => {
+    expect(splitPastedRecipients("   ")).toEqual({ valid: [], invalid: [] });
+  });
+});

lib/email-composer-utils.ts

@@ -1,3 +1,5 @@
+import { isValidEmail } from "@/lib/validation";
+
 const HTML_ESCAPE_MAP = {
   "&": "&",
   "<": "&lt;",
@@ -56,13 +58,16 @@ export function rewriteCidImagesForEditor(html: string): string {
 export type Recipient = { name?: string; email: string };
 
 /**
- * Splits a comma-separated recipient string into individual entries. Commas
+ * Splits a recipient string into individual entries on any character in
- * inside a quoted display name (`"Doo, John" <john@doo.org>`) or angle brackets
+ * `separators`, treating those characters as literal when they sit inside a
- * (`<a,b@x>`) are treated as literal, not separators. Only used at the
+ * quoted display name (`"Doo, John" <john@doo.org>`) or angle brackets
- * (de)serialization boundary — the live composer state is an array, so the UI
+ * (`<a,b@x>`). Trims each part and drops empties.
- * never round-trips through this. Trims each part and drops empties.
+ *
+ * Defaults to comma-only, the (de)serialization boundary used by the composer
+ * state and mailto handling. Pasted lists pass a wider set (see
+ * {@link splitPasteEntries}) because they also use `;` and line breaks.
  */
-export function splitRecipients(value: string): string[] {
+export function splitRecipients(value: string, separators = ','): string[] {
   const result: string[] = [];
   let current = '';
   let inQuotes = false;
@@ -77,7 +82,7 @@ export function splitRecipients(value: string): string[] {
     } else if (ch === '>' && !inQuotes) {
       inAngle = false;
       current += ch;
-    } else if (ch === ',' && !inQuotes && !inAngle) {
+    } else if (separators.includes(ch) && !inQuotes && !inAngle) {
       const trimmed = current.trim();
       if (trimmed) result.push(trimmed);
       current = '';
@@ -140,6 +145,71 @@ export function formatRecipientList(recipients: Recipient[]): string {
   return recipients.map((r) => formatRecipient(r.name, r.email)).join(', ');
 }
 
+/**
+ * Top-level split of a pasted block into recipient entries on commas,
+ * semicolons and newlines (separators inside a quoted name or angle brackets
+ * stay literal). Broader than the comma-only default of {@link splitRecipients}
+ * because pasted lists also use `;` and line breaks as separators.
+ */
+function splitPasteEntries(value: string): string[] {
+  return splitRecipients(value, ',;\n\r');
+}
+
+/**
+ * Splits pasted text into recipient candidates and partitions them: valid email
+ * addresses become `Recipient`s (deduped case-insensitively against
+ * `existingEmails` and within the paste), and everything else is returned as
+ * `invalid` for the caller to drop back into the input field.
+ *
+ * Handles both structured and bare lists, preserving display names:
+ * - `"Name <email>"` (the whole recipient quoted), `Name <email>`, and
+ *   `"Doe, John" <email>` entries are kept intact with their display name.
+ * - Bare-address dumps (`a@x.com b@y.com`, spreadsheet columns, comma/space/
+ *   semicolon/newline separated) split into one chip per address.
+ * - A token wrapped in angle brackets (`<a@x.com>`) is unwrapped before
+ *   validating, so an `a <a@x.com>` fragment still yields the address.
+ */
+export function splitPastedRecipients(
+  text: string,
+  existingEmails: string[] = [],
+): { valid: Recipient[]; invalid: string[] } {
+  const seen = new Set(existingEmails.map((e) => e.toLowerCase()));
+  const valid: Recipient[] = [];
+  const invalid: string[] = [];
+
+  // Adds a recipient if its address is valid and unseen. Returns true when the
+  // entry is fully handled (valid or a known duplicate) so the caller can stop.
+  const tryAdd = (r: Recipient): boolean => {
+    if (!isValidEmail(r.email)) return false;
+    const key = r.email.toLowerCase();
+    if (!seen.has(key)) {
+      seen.add(key);
+      valid.push(r.name ? { name: r.name, email: r.email } : { email: r.email });
+    }
+    return true;
+  };
+
+  // Split on commas, semicolons and newlines in a quote/angle-aware way so a
+  // `"Doe, John" <j@x.com>` or fully-quoted `"Name <email>"` entry stays a
+  // single recipient (separators inside the name or the address are literal).
+  for (const entry of splitPasteEntries(text)) {
+    // 1. Structured: `Name <email>`, a bare address, or the whole
+    //    `Name <email>` wrapped in quotes (unwrap once and retry).
+    if (tryAdd(parseRecipient(entry))) continue;
+    const unwrapped = unquoteName(entry);
+    if (unwrapped !== entry && tryAdd(parseRecipient(unwrapped))) continue;
+
+    // 2. Fallback: a bare-address run (`a@x.com b@y.com`) or a
+    //    `John Doe <j@x.com>` fragment where only the <addr> is valid.
+    //    Whitespace/semicolon-tokenize; leftover tokens stay behind.
+    for (const token of entry.split(/[\s;]+/).map((t) => t.trim()).filter(Boolean)) {
+      if (!tryAdd({ email: token.replace(/^<|>$/g, '') })) invalid.push(token);
+    }
+  }
+
+  return { valid, invalid };
+}
+
 /**
  * Replaces the placeholder src on `<img data-cid="...">` elements with the
  * resolved data URL once the inline blob has been fetched. Leaves images