This morning my mailbox got swamped with over 40 mail problem notifications ("returned mail: see transcript for details") from the MAILER DAEMON at our university. All of them contained the message:
----- The following addresses had permanent fatal errors -----
Message could not be delivered for 1 day
Message will be deleted from queue
Deferred: Connection timed out with ...
and ALL the addresses were from Hotmail (about 50% of our students have Hotmail addresses). I noticed that the message Deferred: Connection timed out with ... referred to different domains within Hotmail: mx1.hotmail.com, mx2.hotmail.com. mx3.hotmail.com., etc.
This could of course be due to a genuine problem with the mail servers at Hotmail, but the fact that the problems come from what seem to be addresses from different servers (mx1.hotmail.com, mx2.hotmail.com. mx3.hotmail.com., etc.) makes me wonder whether Hotmail rejects messages coming from Moodle because of some SPAM filter. I have the feeling that this problem doesn't have to do with SPAM filters because usually they don't trigger these kinds of messages but I thought people who hang out in this forum and who are wiser than me could help me figure out what is going on.
Is anybody experiencing similar problems?
Josep M.
Most of the Hotmail servers (mx1, mx2, mx3, etc.) appear to be on the same subnet (65.54.x.x). If this suddenly happened after a period of time of no problems, then I would suspect a network problem somewhere. If you were rejected because you were suspected of sending spam, the mail bounce would most likely have had a message to that effect. Spam filtering is done after the e-mail has been received, so e-mails wouldn't have bounced as a result of spam filtering.
I wouldn't worry about it. If e-mails continue to bounce, your IP address may have become listed on an RBL list somewhere. Check your IP address against a reputable RBL service (such as Spamhaus) to make sure it hasn't been listed.
--Brian
I wouldn't worry about it. If e-mails continue to bounce, your IP address may have become listed on an RBL list somewhere. Check your IP address against a reputable RBL service (such as Spamhaus) to make sure it hasn't been listed.
--Brian
Thanks Brian,
It turned out our mail server had problems during the weekend. That was the problem. Looks like it was just a coincidence that all the messages that were returned were from Hotmail.
Josep M.
It turned out our mail server had problems during the weekend. That was the problem. Looks like it was just a coincidence that all the messages that were returned were from Hotmail.
Josep M.