• Improve performance by not updating the IMAP Seen flag whenever downloading mails via POP3.

pop3_no_flag_updates = yes
  • Enable some workarounds for Outlook clients so they won’t hang on unexpected data.

pop3_client_workarounds = outlook-no-nulsoe-ns-eoh
  • Use message GUID as POP3 UIDL. For old mails their UIDLs must be migrated using the migration scripts.

pop3_uidl_format = %g