dbmail or dovecot

This question is going to be difficult for many to answer, but please help.

I am trying to setup a Master/Client server setup to run Postfix. The
MASTER server has Postfix & PostgreSQL Client installed on it. The
Master machine is at the backend with PostgreSQL Server installed on it.

All emails will be held on the backend PostgreSQL Server, which is only
accessible from the Postfix/PostgreSQL Server. I hope you get the picture.

I am trying to determine whether I use 'dbmail' or 'dovecot'? I am new
to both of these applications & they both seems interesting. I am a
NEWBIE so it is important to know which one of these two application is
easy to install, setup, maintain & feature rich. It will be nice to see
URL of a site or Screen shots to see how each of them look. I am sure I
am leaving few things out. Please help. I am working on the weekend.

Jennifer