The hardware node that I run on my server is CentOS. I also have several Debian containers on that node under OpenVZ. I'm late upgrading from Squeeze to Wheezy, and I ran into some issues with Dovecot. I first updated a name server, then a web server and had no issues. I next attempted to update my mail server, and had problems with Dovecot. I could no longer access my server and when trying to perform "apt-get upgrade" after my platform migration from Squeeze to Wheezy, the entire system became unusable. Dovecot was complaining about the certificates needing to be moved from /etc/ssl to /etc/dovecot. During the upgrade I always chose to use older versions b/c of configuration file changes in the new packages. Not sure this was the right decision, but I figured everything would have broken worse if i had upgraded all of the software including the crontab to the latest. I backed up my containers before starting with the upgrades, so my mail server has been restored back to the default. I would be greatful for any help anyone can provide. The two primary questions I have are: Should I allow the latest software and configuration files to be installed, or retain existing versions? Has anyone experienced upgrading problems with Dovecot that I mentioned, and how to fix it?