If I had to guess..
Postfix
Sendmail
Exim
ComminigatePro
Beyond those you'd probably see a lot of the free webmail carriers (Gmail,
yahoo, and hotmail/live all use "custom" MTA's) as well as IPSwitch's iMail
and the Windows Server/IIS SMTP service.
-Scott
-----Original Message-----
From: Deepak Jain [mailto:dee...@ai.net]
Sent: Wednesday, August 26, 2009 4:10 PM
To: valdis.kletni...@vt.edu; Sharef Mustafa
Cc: nanog@nanog.org
Subject: RE: MTAs used
> Now, did you want that in terms of "number of copies installed" or
> "amount of mail handled"? There's probably zillions of little Fedora
> and
> Ubuntu boxes running whatever MTA came off the disk that are handling 1
> or 2 pieces of mail a day, and then there's whatever backends are used
> by MSN/Hotmail, Yahoo, AOL, etc. "This MTA packed by weight, not by
> volume.
> Some settling of contents may have occurred during shipping and
> spamming."
>
> (Seriously - if 95% of the mail out there is spam, then the top 4-5
> MTAs are probably the ratware that's sending out the spam. Something
> to consider...)
In keeping with this concept, and turning it around. What MTA is exposed to
the most spam? (1-x) That should tell you what MTA handles the most "good"
mail by also being the destination for the most spam (good, live
recipients).
Or I could be missing something well known about mail flows.
Deepak
