Not a big deal, a full reinstall every 5-6 years is okay. I'm planning full OS update and mailserver reinstall (I'll probably be switching to CentOS 8). Regar

Not a big deal, a full reinstall every 5-6 years is okay. I'm planning full OS update and mailserver reinstall (I'll probably be switching to CentOS 8). Regarding the downtime... Not a big deal either. I already have an mx backup host in place, along with (semi-automated) procedures to imports mails delivered to the mx-backup host into the mx-primary. > It isn't trivial. Well, it isn't super complicated either. It really depends on the degree/detail of your configuration. For the most parts you should be able to copy the old configuration files into the new postfix/dovecot installation and fix errors as they come up. Problems may arise if you have non standard features and/or if you interface with other services.