November 2011 - dovecot

Re: [Dovecot] How can we horizontally scale Dovecot across multiple servers?
by Arlin 03 Nov '11

03 Nov '11

Could anyone please respond to this query. Thank you! From: Arlin [mailto:arlin@mvs.us] Sent: 28 October 2011 17:06 To: 'dovecot(a)dovecot.org' Subject: How can we horizontally scale Dovecot across multiple servers? Hi, How can we horizontally scale Dovecot across multiple servers? Do we require to install independent instances of Dovecot on each server? We are planning to use a NAS/SAN device using ZFS or EFS for email storage. Each logical unit will be of 10TB and similarly as the no: of user increases we are planning to add multiple 10TB units. In this case how we can manage the email storage on multiple volumes from Dovecot. The configuration of our existing system is:- Dovecot 1.0.15 / Maildirs Postfix 2.5.5 Debian 5.0.9 (Lenny) MySQL 5.0.15 Please advise. Thanks in advance. Creative Regards, Arlin

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Re: [Dovecot] Dot Lock timestmap, users disconnections from roundcube
by Maria Arrea 03 Nov '11

03 Nov '11

We use ntpd daemon, all our systems are configured equal. Another thing, this is VM on vmware vsphere 4.1 Regards Maria ----- Original Message ----- From: Ed W Sent: 11/03/11 11:25 AM To: dovecot(a)dovecot.org Subject: Re: [Dovecot] Dot Lock timestmap, users disconnections from roundcube Hi > We are running dovecot 2.0.13 with mdbox+zlib on RHEL 5.7 x64, ext4. We use NTP. Quick check, but by "NTP" you mean the background daemon and you don't have some cron job running ntpdate or similar every so often? No idea, but since it looks like a clock related curiousity, then knowing if the clock is spot on accurate or drifting would be interesting to know? Simple comparison against other machines over a similar period to you having problems might be accurate enough? Good luck Ed W

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Re: [Dovecot] Imap/pop gateway
by Maria Arrea 03 Nov '11

03 Nov '11

If you are going to use an imap proxy for security reasons, consider using a software DIFFERENT than in your real mailboxes. If you use dovecot in your backend, you could use perdition in the frontend. Regards Maria ----- Original Message ----- From: Ed W Sent: 11/03/11 11:31 AM To: Dovecot Mailing List Subject: Re: [Dovecot] Imap/pop gateway On 31/10/2011 22:20, nuno marques wrote: > > > > Hello, > How can i make a imap/pop gateway? that is, putting the mailboxes on a server on the internal network and put the gateway in the dmz. > The question isn't entirely clear, but I *think* you just want to use the normal "proxy" feature of dovecot. This accepts connections on one machine, examines them until the end of the auth stage and passes them onto some other machine based on the results of the auth process Also there are other imap/pop proxies such as nginx That said I'm not sure how much security this really buys you versus port forwarding POP/IMAP ports to your real server? If the proxy machine were to get hacked (over imap?) then the same hack can jump from the proxy to the real server. Also your only exposure in each case is via POP/IMAP, which means you would be mainly chasing buffer overflow vulnerabilities and the like. These can also be mitigated by chrooting the server machine (please consider virtualisation options, it's usually simpler/faster/saner, eg see my favourite: linux-vservers), MAC controls on the dovecot process (grsec/selinux, etc), and compiler extensions (gcc hardened) Good luck Ed W

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[Dovecot] Imap/pop gateway
by nuno marques 03 Nov '11

03 Nov '11

Hello, How can i make a imap/pop gateway? that is, putting the mailboxes on a server on the internal network and put the gateway in the dmz. regards

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[Dovecot] Thunderbird slow in talking with dovecot IMAP AND to sendmail
by Linda Walsh 03 Nov '11

03 Nov '11

I'm trying to find out what's causing this slowdown -- it's INTOLERABLE.... over 1 minute and less than 1% done. (400MB file)... After trying 3 times, I gave up and logged in using X to the server and ran Tbird from there.... Mail sent out in < 1 minute, though the copy to dovecot took about 50% longer. So... I looked at the network trace. and everyfrackin' body was using 4K packet sizes (at the application level!, the window size on TCP was over 64K...but no one was using it)....especially galling with my network's MTU at 9K, BTW, because small packets are really bad on a 1Gb network. sendmail -- 4K, dovecot /ssl, 4K... wazzup .. is t-bird forcing this, or is there some ssl requirement? but it can't just be ssl -- as it's talking to sendmail on port 25 unencrypted (it's a local net anyway)... I could see the entire binary going out in text form... 1 line at a time...a "C" line in sendmail, with lens of 4096...is that some max? I don't see it in the sendmail.cf files...wanted to see if anyone knew of dovecot restrictions that might limit packets to 4k, before I lamblasted the thunderbird people for another act of mindless stupidity (the first being when they decided to cache all your IMAP store on every local client in the client's ROAMING profile...*brilliant*!!!... sides, if I wanted it on local I would have set 'store on local', but in TB3, they know better and change that for me... Something about them being too stupid to use indexing and searching on an imap server? Maybe I just imagined hearing that...

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Re: [Dovecot] doveadm delete-user ?
by Joseph Tam 03 Nov '11

03 Nov '11

Jan-Frode Myklebust writes: > IMHO it would be great if we could both provision and un-provision users > without having the provisioning system mess with files in the > filesystem. Provisioning new users works fine since dovecot will create > all files/directories on first login, but I haven?t found the tools to > un-provison them. > I see "doveadm mailbox delete" can delete individual > mailboxes, but what about indexes, sieve-scripts and home-directories? > Are there any tools to clean out these ? I coundn't find any, so I wrote my own executable cron job that scans the index cache and checks if the corresponding mailbox exists. If not, it echo the commands to remove the stale indices. From there, you can review it, or pipe it into sh. I can post it if there's any interest, but it's not that hard to write. This is only necessary, of course, if you store the indices in a different place than the mail folder. Joseph Tam <jtam.home(a)gmail.com>

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[Dovecot] Upgrading dovecot 1.0.7 -> 2.0.14 / Redhat EL 5.7
by Götz Reinicke 02 Nov '11

02 Nov '11

Hi, recently I debugged some load and performance and 'log out' problems and found an error in the dovecot logs: Error: pipe() failed: Too many open files Googling around and reading some posts led to the conclusion, that my problem is a bug, which will not be removed. So I'm thinking of upgrading to the latest prebuild rpm from here: http://packages.atrpms.net/dist/el5/dovecot/ As far as I understand the upgrading instructions, I'll be save as we dont use special setting, but I'll check all changes. My question: Dose anybody has done such an upgrade yet? Or are there any suggestion or hints? Thanks a lot and best regards. Götz -- Götz Reinicke IT-Koordinator Tel. +49 7141 969 420 Fax +49 7141 969 55 420 E-Mail goetz.reinicke(a)filmakademie.de Filmakademie Baden-Württemberg GmbH Akademiehof 10 71638 Ludwigsburg www.filmakademie.de Eintragung Amtsgericht Stuttgart HRB 205016 Vorsitzender des Aufsichtsrats: Jürgen Walter MdL Staatssekretär im Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg Geschäftsführer: Prof. Thomas Schadt

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[Dovecot] antispam for dovecot 2.0
by Lars Täuber 01 Nov '11

01 Nov '11

Hi! Is there anybody out there who has ported the antispam-storage-1.x.c to antispam-storage-2.0.c? Or is there an alternative to the antispam plugin? Thanks Lars

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[Dovecot] dsync should sync sieve-dirs to!
by Peer Heinlein 01 Nov '11

01 Nov '11

Having dsync to make backups from existing mail-spaces, it would be nice to make dsync syncing the sieve-dirs too. -Otherweise backups aren't complete... Peer -- Heinlein Professional Linux Support GmbH Linux: Akademie - Support - Hosting http://www.heinlein-support.de Tel: 030 / 40 50 51 - 0 Fax: 030 / 40 50 51 - 19 Zwangsangaben lt. §35a GmbHG: HRB 93818 B / Amtsgericht Berlin-Charlottenburg, Geschäftsführer: Peer Heinlein -- Sitz: Berlin

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