The best way to upgrade is to use the Upgrade option available from the dialog admin interface status page Help button. You can also upgrade by downloading the latest version from
http://download.code-crafters.com/ams.exe and installing over the top of your current installation with Abiltiy Mail Server not running of course.
You can move your installation to a new server at any time by simply copying and pasting the "C:\Program Files\Code-Crafters\Ability Mail Server 2" folder to the new server in the same location or elsewhere if you prefer although you'll have to update the shortcuts on the desktop and start menu if you do.
A couple of tips for upgrading to some of our major versions:
2.50 - This version introduced a major WebMail update with enhanced templates adding a big set of new features. Make sure you enable the enhanced template after upgrading. The easiest way to do this is to simply delete the webmail.ini file to reset to all the new default settings for this.
2.60 - This version introduced a major SPAM filtering update with 10 SPAM filters and a new setup wizard for this. Simply run the SPAM wizard and set up for medium level protection. You then need to only set up Bayesian filtering separately as this is more complicated and requires manual individualised settings.
After any major updates you should check all settings in the mail server to make sure that they are secure and as you would like them to be.