diff --git a/src/server.py b/src/server.py
index 29a4d85..1e9b4ba 100644
--- a/src/server.py
+++ b/src/server.py
@@ -503,16 +503,26 @@ async def watch_folder(
     backoff = 5
     max_backoff = 60
 
+    # Hoisted across reconnects so a transient disconnect (e.g. iCloud's
+    # unsolicited FETCH FLAGS during IDLE) doesn't re-baseline the cursor and
+    # silently drop mail that arrived during the reconnect window. Reset only
+    # on first run or when the server's UIDVALIDITY changes (which means UIDs
+    # have been reassigned and the previous cursor is meaningless).
+    last_seen_uid: Optional[int] = None
+    last_uidvalidity: Optional[int] = None
+
     while not stop_event.is_set():
         client = None
         try:
             client = await asyncio.to_thread(get_imap_client, account)
-            await asyncio.to_thread(
+            select_info = await asyncio.to_thread(
                 client.select_folder,
                 folder,
                 readonly=not account.get("mark_as_read", False),
             )
 
+            uidvalidity = select_info.get(b"UIDVALIDITY") if select_info else None
+
             # Check IDLE support
             if not client.has_capability("IDLE"):
                 logger.warning(
@@ -520,21 +530,57 @@ async def watch_folder(
                     account["id"],
                     folder,
                 )
-                await _poll_folder(
-                    client, account, folder, webhook_url, api_key, stop_event
-                )
+                # Mutable cursor state — _poll_folder updates it so reconnects
+                # don't re-baseline.
+                cursor = {
+                    "last_seen_uid": last_seen_uid,
+                    "last_uidvalidity": last_uidvalidity,
+                }
+                try:
+                    await _poll_folder(
+                        client,
+                        account,
+                        folder,
+                        webhook_url,
+                        api_key,
+                        stop_event,
+                        cursor,
+                    )
+                finally:
+                    last_seen_uid = cursor["last_seen_uid"]
+                    last_uidvalidity = cursor["last_uidvalidity"]
+                # _poll_folder only returns when stop_event is set; on errors it
+                # raises and we fall through to the outer reconnect path.
                 return
 
-            mailbox_uids = await asyncio.to_thread(client.search, ["ALL"])
-            last_seen_uid = mailbox_uids[-1] if mailbox_uids else 0
-            logger.info(
-                "[%s/%s] Watching for new emails via IDLE from UID %d (%d existing message(s), mark_as_read=%s)",
-                account["id"],
-                folder,
-                last_seen_uid,
-                len(mailbox_uids),
-                account.get("mark_as_read", False),
-            )
+            if last_seen_uid is None or uidvalidity != last_uidvalidity:
+                if last_uidvalidity is not None and uidvalidity != last_uidvalidity:
+                    logger.warning(
+                        "[%s/%s] UIDVALIDITY changed (%s → %s) — resetting cursor",
+                        account["id"],
+                        folder,
+                        last_uidvalidity,
+                        uidvalidity,
+                    )
+                mailbox_uids = await asyncio.to_thread(client.search, ["ALL"])
+                last_seen_uid = mailbox_uids[-1] if mailbox_uids else 0
+                last_uidvalidity = uidvalidity
+                logger.info(
+                    "[%s/%s] Watching for new emails via IDLE from UID %d (%d existing message(s), mark_as_read=%s)",
+                    account["id"],
+                    folder,
+                    last_seen_uid,
+                    len(mailbox_uids),
+                    account.get("mark_as_read", False),
+                )
+            else:
+                logger.info(
+                    "[%s/%s] Resumed IDLE watch from UID %d (mark_as_read=%s)",
+                    account["id"],
+                    folder,
+                    last_seen_uid,
+                    account.get("mark_as_read", False),
+                )
             backoff = 5
 
             while not stop_event.is_set():
@@ -611,20 +657,35 @@ async def _poll_folder(
     webhook_url: str,
     api_key: str,
     stop_event: asyncio.Event,
+    cursor: dict,
 ):
-    """Fallback polling for servers without IDLE support. Checks every 60 seconds."""
-    mailbox_uids = await asyncio.to_thread(client.search, ["ALL"])
-    last_seen_uid = mailbox_uids[-1] if mailbox_uids else 0
-    logger.info(
-        "[%s/%s] Polling for new emails every 60s from UID %d (%d existing message(s), mark_as_read=%s)",
-        account["id"],
-        folder,
-        last_seen_uid,
-        len(mailbox_uids),
-        account.get("mark_as_read", False),
-    )
+    """Fallback polling for servers without IDLE support. Checks every 60 seconds.
+
+    `cursor` is a mutable dict with keys 'last_seen_uid' and 'last_uidvalidity'
+    shared with watch_folder so cursor state survives reconnects.
+    """
+    if cursor.get("last_seen_uid") is None:
+        mailbox_uids = await asyncio.to_thread(client.search, ["ALL"])
+        cursor["last_seen_uid"] = mailbox_uids[-1] if mailbox_uids else 0
+        logger.info(
+            "[%s/%s] Polling for new emails every 60s from UID %d (%d existing message(s), mark_as_read=%s)",
+            account["id"],
+            folder,
+            cursor["last_seen_uid"],
+            len(mailbox_uids),
+            account.get("mark_as_read", False),
+        )
+    else:
+        logger.info(
+            "[%s/%s] Resumed polling from UID %d (mark_as_read=%s)",
+            account["id"],
+            folder,
+            cursor["last_seen_uid"],
+            account.get("mark_as_read", False),
+        )
     while not stop_event.is_set():
         try:
+            last_seen_uid = cursor["last_seen_uid"]
             mailbox_uids = await asyncio.to_thread(client.search, ["ALL"])
             new_uids = [uid for uid in mailbox_uids if uid > last_seen_uid]
             if new_uids:
@@ -639,12 +700,12 @@ async def _poll_folder(
                 await _forward_uid_batch(
                     client, account, folder, webhook_url, api_key, new_uids
                 )
-                last_seen_uid = new_uids[-1]
+                cursor["last_seen_uid"] = new_uids[-1]
                 logger.debug(
                     "[%s/%s] Advanced UID cursor to %d",
                     account["id"],
                     folder,
-                    last_seen_uid,
+                    cursor["last_seen_uid"],
                 )
             else:
                 logger.debug(