Intermittent SocketTimeoutException On SMTP Connection

Recently, when I compose a message and tap the send button, K-9 Mail reports the following error in Android notifications:

/!\ K-9 Mail
Failed to send some messages
SocketTimeoutException: Read timed out

Within a few minutes, the message delivery is successful. These are the device specifics:

Samsung Galaxy A21
Android 12
K-9 Mail 6.602
IMAP / STARTTLS / port 587 / require sign-in

Any ideas?

1 Like

Does this happen on any network or just specific networks?

Such timeouts can appear depending on the proxy configuration and/or multi-NAT setup. E.g., one of our campuses is connected through one IP, thus all traffic is routed through a squid proxy. If squid has a hickup, K-9’s connection times out rather than detecting the network hickup.


I have not tried on any network, other than my home network, but I will have an opportunity this morning to try another. I’ll let you know if I see any failures. Since the timeout is intermittent, this may not be an adequate test.


I did not have a chance to test SMTP from the other network, so I will keep you posted if I see additional timeouts.

I have the same issue, except it affects ALL of my sent email. They all end up in my Outbox folder. When they finally timeout with that error all I do is choose “send messages” and it works. This happens on my LAN (local dovecot imap) or when I’m remote over the Internet. Ie always fails first time but works on manual retry. Other IMAP clients don’t have this issue

Absolutely same issue.