what was that?

[Nikolaj I. Potanin]

What does mean this bizarre msgid?

maillog:
Mar 31 19:31:15 cu sm-mta[5352]: h2VFVEGS005352: from=<nb at sindbad.ru>, 
size=1737, class=0, nrcpts=1, 
msgid=<!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAAfp4Fa2ShPE2u4pP/QpPDIMKAAAAQAAAAj+zb4Isbuk+tYEPVF9Vf, 
proto=ESMTP, daemon=MTA, relay=wg.pu.ru [193.124.85.219]

-- 
Nikolaj I. Potanin, SA                          http://www.drweb.ru
ID Anti-Virus Lab (SalD Ltd)                    nikolaj at drweb.ru
St. Petersburg, Russia                          ph.: +7-812-3888624