Since you have confirmed that someone else you know is using it on FreeBSD+ZFS without these problems, have you tried asking on the FreeBSD support list(s)?
Seems like that may be your best bet, since it is certainly not a generic dovecot problem (but may indeed be one or more of the settings you are using)...
You could also go ahead and post the diff of your config and your friends (I'm fairly sure this list is small attachment friendly, but I recommend pasted it in the email body anyway) and see if anything jumps out at anyone/Timo...
On 4/18/2015 10:34 PM, David Gessel <gessel@blackrosetech.com> wrote:
-------- Original Message -------- Subject: Re: Dovecot 2.2.16: disappearing messages, mismatched summaries, duplicated messages, excessive full re-downloads From: David Gessel <gessel@blackrosetech.com> To: Timo Sirainen <tss@iki.fi> Date: Sat Apr 18 2015 20:35:40 GMT+0300 (Arabic Standard Time)
THANKS TIMO!
-------- Original Message -------- Subject: Re: Dovecot 2.2.16: disappearing messages, mismatched summaries, duplicated messages, excessive full re-downloads From: Timo Sirainen <tss@iki.fi> To: David Gessel <gessel@blackrosetech.com> Date: Sat Apr 18 2015 17:38:02 GMT+0300 (Arabic Standard Time)
Actually as a workaround you could try maildir_very_dirty_syncs=yes which gets rid of most of the readdir()s. I will try that right now and report any differences in behavior!
Alas, it hasn't solved the problem - still getting duplicate messages in thunderbird. So far it appears that mulberry is a little happier, but I find some messages are missing - such as the archive of the dovecot mailing list jumping from 2015-03-21 to 2015-04-14.
I tried # rm -r dovecot.id*
Would "maildir_broken_filename_sizes = yes" have any impact? If it does, then I'd think your fix sizes script would be worth a try.
If all that fails - is there any reason to think that sdbox will be better behaved?
-David