diff --git a/frappe/email/receive.py b/frappe/email/receive.py
index 1ddf69afcb..8ad99777d9 100644
--- a/frappe/email/receive.py
+++ b/frappe/email/receive.py
@@ -219,6 +219,9 @@ class EmailServer:
 		uidnext = int(self.parse_imap_response("UIDNEXT", message[0]) or "1")
 		frappe.db.set_value("Email Account", self.settings.email_account, "uidnext", uidnext)
 
+		if uid_validity is None:
+			frappe.flags.initial_sync = True
+
 		if not uid_validity or uid_validity != current_uid_validity:
 			# uidvalidity changed & all email uids are reindexed by server
 			frappe.db.set_value(