Postfix and Dovecot work fine together. It's a one-time effort to set it up and it will work for many years. Most of the work will go into setting up spam filte

Postfix and Dovecot work fine together. It's a one-time effort to set it up and it will work for many years. Most of the work will go into setting up spam filtering (Spamassassin), some virus-scanner if you want to bother (Amavis) and perhaps the Anomy Mail Sanitizer, which has served us well over the years, as well as the task of setting up SSL/TLS for SMTP, unless Ubuntu has taken care of that already (Debian Squeeze hasn't ...). Unfortunately, all Open Source webmail clients I know of (including Redcube, Horde) are cumbersome if you have used Gmail and Fastmail.