Hi,
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.
I don't know Alpine but I can imagine, that Alpine creates TCP
connection to IMAPS and uses IDLE. I read wiki page about Timeouts [1]
and it seems OK. Alpine is connected 5 or more hours without interrupt.
But I found 'Connection closed' at approximate times of user reports in
mail.log.
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.
I can imagine that such situations may happend for moving clients, such
a smartphone with losing signal. But mentioned user is on local network
connected by cable.
I'm interested, what exactly 'Connection closed' in mail log means. We
have following lines in log:
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
imap(username): Connection closed: read(size=3751) failed: Connection
reset by peer in=4441 out=51431
dovecot: imap(username): Connection closed (UID fetch running for 0.008
+ waiting input for 0.001 secs, 0.001 in locks, 101 B in + 202+202 B
out, state=wait-input) in=3330 out=436043
Could it be problem in our network or Dovecot configuration issue? Can I
somehow debug all connections for single client?
Thank you, Milo
[1] https://wiki.dovecot.org/Timeouts
