Hi list,

running Dovecot 2.2.27 on Ubuntu 14.04. A public mailbox "Public/Spam-Learning" in a public namespace with per-user "Seen" flags is configured like this:

namespace pub { hidden = no inbox = no list = children location = maildir:/var/vmail/public:INDEXPVT=~/Maildir/public prefix = Public/ separator = / subscriptions = no type = public mailbox "Spam-Learning" { auto = subscribe } }

The log files are full of error messages like these (got about 15000 in the last three days):

2017-01-03T11:19:28.242386+01:00 mailserver01 dovecot: imap(foo.bar@example.org): Error: /var/vmail/example.org/foo.bar/Maildir/public/.Spam-Learning/dovecot.index.pvt reset, view is now inconsistent 2017-01-03T11:19:28.248524+01:00 mailserver01 dovecot: imap(foo.bar@example.org): Error: /var/vmail/example.org/foo.bar/Maildir/public/.Spam-Learning/dovecot.index.pvt view is inconsistent 2017-01-03T11:23:50.209732+01:00 mailserver01 dovecot: imap(baz.quux@example.org): Error: /var/vmail/example.org/baz.quux/Maildir/public/.Spam-Learning/dovecot.index.pvt reset, view is now inconsistent 2017-01-03T11:23:50.775940+01:00 mailserver01 dovecot: imap(some.user@example.org): Error: /var/vmail/example.org/some.user/Maildir/public/.Spam-Learning/dovecot.index.pvt reset, view is now inconsistent 2017-01-03T11:25:38.419536+01:00 mailserver01 dovecot: imap(other.user@example.org): Error: /var/vmail/example.org/other.user/Maildir/public/.Spam-Learning/dovecot.index.pvt reset, view is now inconsistent 2017-01-03T11:34:14.351346+01:00 mailserver01 dovecot: imap(more.user@example.org): Error: /var/vmail/example.org/more.user/Maildir/public/.Spam-Learning/dovecot.index.pvt reset, view is now inconsistent 2017-01-03T11:41:37.488916+01:00 mailserver01 dovecot: imap(support.user@example.org): Error: /var/vmail/example.org/support.user/Maildir/public/.Spam-Learning/dovecot.index.pvt reset, view is now inconsistent

This problem did not seem to manifest itself in Dovecot 2.2.25, we see it only after upgrading to 2.2.27.

I am not sure what the effects are. It seems that messages moved to the Public/Spam-Learning folder are deleted after a short while (not by the sa-learn cron job, which runs every morning) but I currently cannot say if this is because a user deletes them explicitly or because Dovecot does something it shouldn't. So this observation is possibly not relevant.

It also doesn't seem to matter what kind of IMAP client access the Spam-Learning folder. Our users use Thunderbird, Apple Mail, Outlook, Roundcube, Horde and various mobile clients as well.

I have attached the output of doveconf -n for reference.

What could be the issue here? Are we doing something wrong or is this a bug in Dovecot?

Thanks!

Andreas