Hello! I was wondering if anyone knows of a Web site that polls SMTP servers and gathers statistics of the most popular MTAs? Our company is considering replacing our Sendmail UNIX mail relays with Microsoft Exchange. I definitely do not share this vision, and wanted to gather as much evidence as possible that open-source MTAs--Sendmail, Qmail, Postfix, Exim, others--are the most popular choice for mail relays, particularly for high-volume sites. Does anyone have a list of major ISPs/big corporations/other high profile sites/and what MTAs they use? Also, any other information on why we should NOT use Exchange would be greatly appreciated! I know I'm going to be over my head in FUD and would want to provide facts instead of (only) zealotry :D Thanks in advance! Brandon