[Dovecot] phantom new mail (mailboxes keep on being reported as having new mail)

[Grobian]

This problem gets rather annoying.  Isn't there anything that I can try
to resolve this?  It dovecot can't work so well with its indices, is
there an option to disable them?  I keep on deleting those files to get
rid of phantom new mail.


On 09-03-2006 20:21:26 +0100, Grobian wrote:
> Hi,
> 
> I'm using dovecot 1.0_beta3 on Gentoo Linux, and am experiencing a
> problem of what I call 'phantom mail'.  This problem I have for a long
> time (pre 1.0), but at the moment I'm using 1.0_beta3 and the problem
> still is in there.
> 
> My setup is as follows:
> - regular x86 box
> - running Exim and Dovecot
> - Exim saves new mail in maildir format in a local filesystem
>   /mail/user/blabla
> - Dovecot reads and serves IMAP from local filesystem /mail/user/blabla
> - client is Mutt and/or Thunderbird from any OS (Mac, Linux, Windows)
>   via IMAP
> 
> Situation that happens:
> I get new mail in a folder, say =news (in Mutt style, it's .news dir in
> the maildir directory).  I read the item, Mutt (or Thunderbird) marks
> the item as read (moving it over to cur aswell I think), save the
> folder, then move on to another folder.  At this point dovecot IMAP
> server indicates to the client that there is new mail in the folder
> =news.  If I visit the folder with the client, I see no new mail, and
> sometimes I have two or three of those folders, and I can keep on
> cycling with Mutt till I get bored :).
> Before upgrading Dovecot, I knew of no way to resolve this problem;
> eventually, it seemed that at some point the folder seemed to figure out
> itself that there was indeed no new mail.  Sometimes I could trick it by
> letting Mutt mark the mail as new again, and then save the folder.
> Didn't always work.
> Now, I think a week or two ago I upgraded Dovecot and had to manually
> move all the .subscription files, and I also in one go decided to remove
> the dovecot* and .imap* files.  That cleaned up, and at first that
> looked like it solved my problem.  Not.  So I figured out throwing away
> dovecot's index stuff (rm dovecot* in the directory that shows phantom
> mail) resolves the problem.  However, this method starts to get annoying
> so to say.
> 
> So, I did some investigation and found out that the dovecot-uidlist file
> seems to be not up-to-date on a folder that shows phantom mails:
> 
> # awk '{ print $2 }' dovecot-uidlist | sort > tmp.uids
> # ls cur | sort | diff -u - tmp.uids
> --- -   2006-03-08 17:45:26.428168000 +0100
> +++ tmp.uids    2006-03-08 17:45:19.000000000 +0100
> @@ -47,4 +47,5 @@
>  1141340181.H111425P8973.hermes.orakel.ods.org:2,S
>  1141387968.P13010Q0M35974.hermes:2,S
>  1141528391.H769531P12886.hermes.orakel.ods.org:2,S
> -1141830301.H349821P23427.hermes.orakel.ods.org:2,S
> +1141544380
> +1141830301.H349821P23427.hermes.orakel.ods.org
> 
> It seems the dovecot uidlist doesn't have the right name for the file on
> disk, probably therefore "seeing" a new file all the time and reporting
> the folder as having new mail.  The 1141544380 entry comes from the
> first row of the dovecot-uidlist file:
> 1 1141544380 51
> I guess it's just some sort of line to keep track of the last timestamp
> and the number of messages or something.  If my theory is right here
> then it looks as if the 'bad entry' is actually more recent than this
> most recent timestamp reports.  But this is only speculation of course.
> 
> Enough for this lenghty mail I guess.  Is this a known issue, or can it
> be caused by the way I set up my system?  I must note that this only
> happens for some folders, not all of them.  I have folders which get a
> lot of mail, but don't have this happening on.  Any clues go resolve
> this are welcome.
> 
> 
> Regards,
> 

-- 
Fabian Groffen
Gentoo for Mac OS X Project