[Skunkworks] Doodle Poll - What MTA's do you use?

Hi Skunkworks, As part of a project am working on we would like to know what Mail Transfer Agent (MTA) most folks are using. Please note that we are polling for Open Source side MTAs. If you are using something like Zimbra Suite, you can pick Postfix since its the MTA in use. All this is to try and help make a decision on which MTA should we develop course materials for based on its popularity in the region. The URL is http://www.doodle.com/ncnpty982dwf6488 Thanks for your help. Regards, Michuki.