Connection closed reason

[Joseph Tam]

Miloslav H?la <miloslav.hula at gmail.com>

> we have one user using the old Alpine client with IMAP. Time to time (3
> times per day or 3 times per week) he get error: "MAIL FOLDER INBOX
> CLOSED DUE TO ACCESS ERROR" and he complains, that inbox stops to
> refresh with new emails.

Hmm, I see when using direct file access, but not when
using IMAP, but I don't often connect this way with alpine).

> Am'I undestand it correctly, that 'Connection closed' is some kind of
> incorrect connection end? I can find 'Logged out' messages which seems
> to me as correct ones.
> ...
> dovecot: imap(username): Connection closed in=63 out=288442
> dovecot: imap(username): Connection closed (IDLE running for 0.001 +
> waiting input for 0.001 secs, 2 B in + 10+0 B out, state=wait-input)
> in=9668 out=17375

I was able to simulate this using netcat -- this log message comes when
the client closes the connection during IDLE.

> imap(username): Connection closed: read(size=3751) failed: Connection
> reset by peer in=4441 out=51431

I couldn't recreate this, but this happens when the client sends an
immediate TCP RST connection teardown packet, rather than the usual
FIN/ACK/RST orderly shutdown.

I don't know what would cause this -- maybe some firewall state session
timeout?

Joseph Tam <jtam.home at gmail.com>