Multiple webserver, email configuration
 

Hello Guys,

We run our site on 3 front end servers and a DB server. One of the front end servers run cpanel and has exim configured just right. However the other two have sendmail on them.

In such a setup, how does the lack of queueing hurt? or it does not? What would be the best way to configure such a setup so that all emails go through one server which has the appropriate domain keys etc.

Also the size of the forum is large with around 300,000 users and they received newsletters etc as well.

Thoughts?