Ever wonder what mail servers people run? I found myself wondering what the top universities used, so I wrote a lame little script to go and query the top 50 schools from this list, find out their mail servers, and then netcat to them to see what they respond with.
220 mailhub4.dartmouth.edu ESMTP Sendmail 8.13.5/DND2.0/8.13.5; Tue, 9 May 2006 17:06:16 -0400
220 ns3.br.harvard.edu ESMTP Postfix
220 nisc.net.isc.upenn.edu ESMTP Postfix
220 emfw1.Princeton.EDU ESMTP (0ebdea0d60768e14e7c57b1a3713dd99)
220 mr5.its.yale.edu ESMTP server ready at Tue, 9 May 2006 17:06:18 -0400
220 MIT.EDU ESMTP Sendmail (no collect or third party calls) at Tue, 9 May 2006 17:06:19 -0400 (EDT)
220 water-ox.its.caltech.edu ESMTP Postfix
220 mx4.stanford.edu ESMTP Postfix
220-pohl.acpub.duke.edu ESMTP Duke University Sendmail 8.12.10/Duke-5.0.0;
220 MailRouter-2.wustl.edu ESMTP Mirapoint 3.5.8-GR; Tue, 9 May 2006 16:06:26 -0500 (CDT)
220 relay.it.northwestern.edu ESMTP Postfix
220 ipex2.johnshopkins.edu ESMTP
So out of 36 responses I got 7 with Postfix in the banner. If we take that highly unscientific sample and call it legit, we’re looking at roughly 20% of top-50 universities using Postfix. Not bad.
Aside from the MTA war, though, it was just interesting to see what these guys were putting in their banners. Check out the Princeton one, for example — they have some sort of secret message encoded with MD5 in theirs. And MIT points out that they don’t want any collect or third party calls. Nice.
Anyway, here are the results and the tool I used. Be sure to check out the raw output as well; there are quite a few interesting tidbits in there.: