Fetch full messages with BODY.PEEK[] so read_email works on iCloud IMAP (#1961) (#1963)

read_email, reply_to_email and download_attachment fetched the full message with
the legacy bare RFC822 item (UID FETCH <uid> (RFC822)). iCloud's IMAP server
silently ignores it — the fetch returns status OK but only (UID <uid>) with no
body tuple, so the parse reports 'Email not found with UID' even though the
message exists and list_emails (which uses RFC822.HEADER) shows it. Gmail honours
(RFC822), which is why it only reproduced on iCloud.

Switch the three full-message fetches to (BODY.PEEK[]), which iCloud and Gmail
both honour and which doesn't set \Seen. Response shape is unchanged (raw bytes
still at msg_data[0][1]), so parsing is unaffected; the RFC822.HEADER (listing)
and (UID) probe fetches are left as-is.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

mcp_servers/email_server.py

@@ -666,7 +666,7 @@ def _read_email(uid=None, message_id=None, folder="INBOX", account=None):
         conn.logout()
         return {"error": "No UID or Message-ID provided"}
 
-    status, msg_data = conn.uid("FETCH", _b(uid), "(RFC822)")
+    status, msg_data = conn.uid("FETCH", _b(uid), "(BODY.PEEK[])")
     if status != "OK":
         conn.logout()
         return {"error": f"Failed to fetch email UID {uid}"}
@@ -855,7 +855,7 @@ def _reply_to_email(uid, body, folder="INBOX", reply_all=False, account=None):
     """Reply to an existing email by UID. Threads via In-Reply-To/References."""
     conn = _imap_connect(account)
     conn.select(folder, readonly=True)
-    status, msg_data = conn.uid("FETCH", _b(uid), "(RFC822)")
+    status, msg_data = conn.uid("FETCH", _b(uid), "(BODY.PEEK[])")
     conn.logout()
     if status != "OK" or not msg_data or not msg_data[0]:
         return {"error": f"Failed to fetch email UID {uid}"}
@@ -1033,7 +1033,7 @@ def _download_attachment(uid, index, folder="INBOX", account=None):
     """Extract a specific attachment to disk and return its local path."""
     conn = _imap_connect(account)
     conn.select(folder, readonly=True)
-    status, msg_data = conn.uid("FETCH", _b(uid), "(RFC822)")
+    status, msg_data = conn.uid("FETCH", _b(uid), "(BODY.PEEK[])")
     conn.logout()
     if status != "OK":
         return {"error": f"Failed to fetch email UID {uid}"}

tests/test_icloud_imap_full_fetch.py

@@ -0,0 +1,41 @@
+"""Regression for issue #1961 — read_email (and reply_to_email,
+download_attachment) failed on iCloud IMAP accounts.
+
+iCloud's IMAP server silently ignores the legacy bare `RFC822` fetch item: a
+`UID FETCH <uid> (RFC822)` returns status OK but only `(UID <uid>)` with no body
+tuple, so the parse treats the message as "not found" — even though list_emails
+works (it uses `RFC822.HEADER`, which iCloud honours). The modern
+`BODY.PEEK[]` item is honoured by iCloud and Gmail alike and doesn't set \\Seen.
+
+The fix is an IMAP-protocol-string change exercised only against a live server,
+so it's guarded at the source here (per CONTRIBUTING's "guard at source" note):
+the three full-message fetches must use BODY.PEEK[], and no bare (RFC822) full
+fetch may remain. The header/uid fetches must be left untouched so listing keeps
+working.
+"""
+import re
+from pathlib import Path
+
+SRC = (Path(__file__).resolve().parent.parent / "mcp_servers/email_server.py").read_text(encoding="utf-8")
+
+
+def _full_fetches():
+    # every conn.uid("FETCH", ..., "<item>") call's fetch item
+    return re.findall(r'conn\.uid\(\s*"FETCH"\s*,[^,]+,\s*"([^"]+)"\s*\)', SRC)
+
+
+def test_full_message_fetches_use_body_peek_not_bare_rfc822():
+    items = _full_fetches()
+    assert items, "no conn.uid FETCH calls found — test anchor stale"
+    # No bare (RFC822) full-message fetch may remain (it breaks iCloud).
+    assert "(RFC822)" not in items, f"a bare (RFC822) full fetch remains: {items}"
+    # The full-message reads now use BODY.PEEK[] — at least the 3 known sites.
+    assert items.count("(BODY.PEEK[])") >= 3, f"expected >=3 BODY.PEEK[] fetches: {items}"
+
+
+def test_header_and_uid_fetches_preserved():
+    items = _full_fetches()
+    # Listing relies on RFC822.HEADER (iCloud honours it) — must stay.
+    assert "(RFC822.HEADER)" in items, "RFC822.HEADER fetch (used by listing) must be preserved"
+    # UID-only probes must stay as-is.
+    assert "(UID)" in items, "(UID) probe fetch must be preserved"