Just out of curiosity I was wondering if anyone knew whats happening with my server to make it do what it is doing. We recently upgraded from Ubuntu 11.10 to Ubuntu 12.04. However since that update we have had to constantly restart the mail server atleast on an hourly basis as the emails just stop responding and the webmail wont allow people to login (Both Roundcube and Squirrelmail). Once the server has been restarted it operates as expected for about 1-2 hour(s) then crashes again. This issue is causing us a lot of issues as we provide hosting and emails for people and it could not be a worse time for this to start messing up. If anyone knows what to do, to look for, or would like some more information to help please just ask and i will provide any information needed.