Before anything else, isolate where the problem lives:
- Test webmail at ukbox.host:2096. If webmail sends and receives normally, your mailbox and server are healthy — the issue is device settings (see our IMAP settings article and re-add the account).
- Check mailbox storage — a full mailbox silently rejects new mail. Webmail shows usage.
- Recently migrated to us? Leftover MX records at your old DNS host can misroute incoming mail — we can check and fix your records in minutes.
Still stuck? Open a ticket with the exact error message (screenshot ideal), one affected address, and whether it's sending, receiving or both.
