In the past few days, our mail server developed an issue resulting in approximately 30,000 spam messages being held in a queue. When the issue was resolved, all 30,000 messages were immediately delivered.
Some of our users forward their e-mail to @hotmail.com and @telus.net addresses. It appears that the sudden increase in the volume of spam messages that were being forwarded through our system - but *did not* originate from our system - has resulted in our mail server being blacklisted by Hotmail and Telus. Messages sent through Antiflux to those systems bounce back with messages like these.
Hotmail:
host mx3.hotmail.com[65.54.244.72] said: 550
Command rejected for policy reasons. (in reply to MAIL FROM command)
Telus:
host mx.svc.telus.net[204.209.205.52] said: 554 Service unavailable;
[216.234.161.200] RBL blocked (in reply to RCPT TO command)
We have contacted Hotmail and Telus (using non-Antiflux email accounts) about the issue. Hotmail replied saying they would investigate. As of 2006-09-20, we have not heard anything from Telus.
If you get a bounce message from somewhere other than Telus or Hotmail, please let us know.
Update: As of Wednesday evening, Telus and Hotmail are both accepting mail from Antiflux again.