Great Moments in SMTP Conversations
Most people online don’t know this unless they’re a support tech. When you send an email your SMTP server actually has a little conversation with the recipient’s mail server. They issue commands back and forth, acknowledge the commands, and process the mail.
Today while looking at a server’s email queue run logs I noticed the following choice bit of server admin humor:
SMTP<< 220 xxxx.xxx.xxx.xxxxx.xx ESMTP spamd IP-based SPAM blocker; Sat Aug 18 08:14:39 2007 SMTP>> EHLO xxxx.xxxxxx.xxx
SMTP<< 250 Hello, spam sender. Pleased to be wasting your time. SMTP>> MAIL FROM email@example.com
SMTP<< 250 You are about to try to deliver spam. Your time will be spent, for nothing. SMTP>> RCPT TO: firstname.lastname@example.org
SMTP<< 250 This is hurting you more than it is hurting me. SMTP>> DATA
The best part is the server that was receiving the mail (issuing the “hello spammer” responses) intentionally slowed each of its responses down to keep the other server busy. This type of setup actually costs spammers money as a transaction that normally takes under a second is now taking over 3 minutes.