OT: Is Microsoft using postfix in their MXs?

[Manuel Mely]

Today i have been involved in some discussion about Zimbra vs  Exchange 
2007. I don't know why, i decided to look for what Microsoft is using in 
their MXs and i found this:

$ telnet 216.32.180.22 25
Trying 216.32.180.22...
Connected to 216.32.180.22.
Escape character is '^]'.
220 mail85-va3.bigfish.com ESMTP Postfix EGGS and Butter
quit
221 Bye
Connection closed by foreign host.
Is this real or is just a changed banner?

Greetings