Mail server saturation


I use webmin to host some of my website. When all person that use our server for their mail (10 person use simultaneous, trought iMap and Mozilla ThunderBird, some of them use same account simultaneously).

When all person use their Mozilla, we have a problem, server don’t reply and we cannot read new mail or send an email correctly (the email was sended, but isn’t copied on the server, Mozilla said that he can’t copy the mail to the outbound folder). And if i try to read mail in the same time trought Virtualmin WEBMAIL, it was ver very very slow…

Have you an idea to solve my problem?

I think that we have limited process that run IMAP, can i unlimit them?

Please note that we run Ubuntu on an OpenVZ.



Well, 10 users accessing email isn’t actually very much – servers can typically handle hundreds of simultaneous email users.

How much RAM does your server have? You can determine that by running “free -m”.

Also, what is the output of this command:

cat /proc/user_beancounters

I think that i made a mistake, each user have 7-10 mail accounts (5 of them are common to all users, and used permanently trought thunderbird).

In the morning, before everyone start to working, cat says :

You can see on this link more cat, when we are in charge and when the problem come.

You can see on this link more cat, when we are in charge and when the problem come.

Well, that part looks normal. I had wondered if maybe you were running into any OpenVZ resource limits, as that’s a common source of problems.

How about RAM – what does “free -m” look like on your system?

I’ve seen systems with hundreds of domains and thousands of email accounts run perfectly normal on a default installation without having to modify any resource settings for Dovecot (IMAP/POP) – so I’m looking to see if there’s any other issues going on before we look into Dovecot-specific issues.



Here the extrat of free -m command…

Thanks for your help