Quoting Scott Dier (dieman+tclug at ringworld.org):
> * Steve Siegfried <sos at zjod.net> [010910 15:55]:
> > > Sep 10 15:17:37 foo tcplog: smtp connection attempt from [sHSnPtG/0WxsLlmmpmE6Aw+qwOBD7SKt]@lists.real-time.com:1997
> 
> No, hes using random ident to do that.  I dont know if / is valid,
> however, it probally is.
> 

See my previous post. It's a Base64 string of a triple-DES encryption of the
user of the smtp process.
-- 
Bob Tanner <tanner at real-time.com>       | Phone : (952)943-8700
http://www.mn-linux.org                 | Fax   : (952)943-8500
Key fingerprint =  6C E9 51 4F D5 3E 4C 66 62 A9 10 E5 35 85 39 D9