Ask Your Question

IMAP server has unexpectedly disconnected

asked 2024-05-25 07:56:35 +0000

sugar76 gravatar image

On a client machine, we receive quite regularly error messages from the mail client

2024-05-24 16:10:42,578 [25] ERROR Betreuung.Service.EmailService2 Fehler beim E-Mail-Empfang für Konto [email protected].
Betreuung.Email.EmailServiceException: Konnte keine Verbindung zum E-Mail-Server herstellen. Fehlermeldung: The IMAP server has unexpectedly disconnected.

I recorded a capture which you can find here.

First see the DNS query at packet no. 38. Then some TLS protocol packets are exchanged and at packet 69 and 70 something bad happens (don't know what).

Does the packet capture indicate an issue on my side or on the server's side? Does it provide any issue details which I oversee?

edit retag flag offensive close merge delete


The shared file is not public...

SYN-bit gravatar imageSYN-bit ( 2024-05-27 22:08:32 +0000 )edit

1 Answer

Sort by » oldest newest most voted

answered 2024-05-28 10:24:10 +0000

SYN-bit gravatar image

Thanks for sharing the file, the RST packets in frame 69/70 are sent after a FIN from both sides, so that should be nothing to worry about. Some TLS libraries do this to clean up sessions.

Why the IMAP server disconnects the client can only be determined with decryption or from extended logging in the client or the server.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

1 follower


Asked: 2024-05-25 07:56:35 +0000

Seen: 160 times

Last updated: May 28