- dovecot - dovecot.org

Re: [Dovecot] Dot Lock timestmap, users disconnections from roundcube
by Maria Arrea 04 Nov '11

04 Nov '11

We follow the guidelines about timekeeping RHEL in vmware vsphere located here http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=di… These problems happens in peak hours. Any dovecot config parameter I could set to mitigate this problem? Regards Maria ----- Original Message ----- From: Ed W Sent: 11/03/11 11:57 AM To: Maria Arrea, Dovecot Mailing List Subject: Re: [Dovecot] Dot Lock timestmap, users disconnections from roundcube On 03/11/2011 10:49, Maria Arrea wrote: > All the ESXs hosts and all the VM use the same NTP server. > > Any other idea? > Doesn't ESX have issues with the time drifting when certain kernel options are set? Something to do with it rescheduling machines and them not counting idle ticks or something..? Does this problem happen during idle hours or peak hours? I should home in on clock problems... Probably vmware related issues to the kernel you are using? Good luck Ed W

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[Dovecot] Difference between LOGIN and PLAIN
by Simon Brereton 04 Nov '11

04 Nov '11

Hi Could someone explain to me the difference between LOGIN and PLAIN? I've been googling for a while, but haven't found anything. Thanks. Simon

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[Dovecot] How can we horizontally scale Dovecot across multiple servers?
by Arlin 04 Nov '11

04 Nov '11

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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[Dovecot] looking for Dovecot-code + SQL consultants
by Rich 03 Nov '11

03 Nov '11

Hi, We're using Dovecot2. Trying, given our own spread-too-thin bandwidth, to make it work within our evolving SQL application environment. When there's a problem, we post to this list (e.g., http://www.dovecot.org/list/dovecot/2011-October/061609.html) but aren't getting any/timely responses. We've decided to look for a consultant (hourly or retainer) that can be available for working with our in-house staff to straighten these issues out -- by helping us identify & fix our own mess, and by working to get fixes pushed to Dovecot project code, where appropriate. If you provide these services, rather than simply deployment or hosting, and are available, please drop me a line *offlist*. We're in the San Francisco area, and local is best, but remote work is certainly an option. Thanks, Rich

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

03 Nov '11

All the ESXs hosts and all the VM use the same NTP server. Any other idea? Regards Maria ----- Original Message ----- From: Giulio Casella Sent: 11/03/11 11:38 AM To: dovecot(a)dovecot.org Subject: Re: [Dovecot] Dot Lock timestmap, users disconnections from roundcube This could be the problem. Double check the time also on your host system(s), not only on guest. Bye, gc Il 03/11/2011 11.30, Maria Arrea ha scritto: > 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 > -- Giulio Casella giulio at dsi.unimi.it System and network manager Computer Science Dept. - University of Milano

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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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