dovecot refuses connection after upgrade

[The Crazy Dutch Bastard]

after upgrading my ubuntu-server from 8.10 to 9.04 i was unable to connect to my imap folder. for some reason or another it changed the config file to only listen on ipv6.

to fix this go to /etc/dovecot/dovecot.conf and make sure listen is set to Listen = *

[Chuck Short (zulcss)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Unfortunately, we can't fix it because your description didn't include enough information. You may find it helpful to read "How to report bugs effectively" http://www.chiark.greenend.org.uk/~sgtatham/bugs.html. We'd be grateful if you would then provide a more complete description of the problem. We have instructions on debugging some types of problems at http://wiki.ubuntu.com/DebuggingProcedures.
At a minimum, we need:
1. the specific steps or actions you took that caused you to encounter the problem,
2. the behavior you expected, and
3. the behavior you actually encountered (in as much detail as possible).
Thanks!

When reporting bugs in the future please use apport, either via the appropriate application's "Help -> Report a Problem" menu or using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Chuck Short (zulcss)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!

[TJ (tj)]

Confirming this affects a Hardy LTS >? Lucid LTS upgrade.

The symptoms are that after the upgrade IMAP4 clients cannot connect to the server, but there are few clues.

After sorting out the other issues caused by the upgrade such as pointing dovecot to the /etc/ssl/certs/$CERT.{pem,key} I hit this one.

Nothing at all was appearing in /var/log/dovecot.log about connections. There were entries showing the dovecot processes were starting, and ps -ef A grep dovecot showed they were running.

I enabled "auth_debug = yes" but no clues appeared.

Then I check the network connections and noticed there were no IPv4 sockets being used:

sudo -i
netstat -tlnp | grep dovecot
tcp6 0 0 :::993 :::* LISTEN 7933/dovecot
tcp6 0 0 :::995 :::* LISTEN 7933/dovecot
tcp6 0 0 :::110 :::* LISTEN 7933/dovecot
tcp6 0 0 :::143 :::* LISTEN 7933/dovecot

Looking in the unedited "/etc/dovecot/dovecot.conf" inherited from Hardy I found:

listen = [::]

In the comments above that is the clue to the solution:

"[::]" listens in all IPv6 interfaces, but may also listen in all IPv4
# interfaces depending on the operating system.

It seems that on Hardy that it would listen on both IPv6 and IPv4 sockets, but now it is more specific.

I changed it to:

listen = *

Restarting dovecot solved the problem and clients connected once more.

[Bryce Harrington (bryce)]

Closing as out of date since it has been 10 years since the last comment.

If this or a similar issue is still a problem with currently supported dovecot, a fresh bug report would be helpful.