Hotmail Out Of Memory

matthew's picture

Just had a funny entry scroll past my window. We use sender address verification where I work to confirm that a sender, in fact, exists at the domain from which the mail is purported to be sent. Some spam just came our way claiming to be from hotmail, so of course Postfix (our mail transfer agent) ran out to Hotmail to make sure the user existed. What do we get on the reply? (a couple names changed to protect our network)

Aug 28 14:18:32 bubba postfix/smtpd[6705]: 1AA1FB8024: reject: RCPT from[]: 450 <>: Sender address rejected: unverified address: host[] said: 452 Out of memory (in reply to MAIL FROM command); from=<> to=<> proto=ESMTP helo=<>

Hotmail ran out of memory? They have to be getting slammed by something, they run some pretty beefy mail servers.