I have recently re-enabled my Spamcop account as my ISP's own filtering was too leaky. I have Spamcop set up to retrieve mail from 2 external POP accounts. I came in this morning to find very little email from over the weekend. Great! I thought, I would usually have lots of spam. However, the morning drew on and I wasn't receiving any non-spam either. I sent my self a message from a Gmail account to test it and I got this back:
The following message to <myspamcopuser[at]spamcop.net> was undeliverable.
The reason for the problem:
5.1.2 - Bad destination host 'DNS Hard Error looking up filter2.cesmail.net (MX): NXDomain'
All of my clients have been receiving the same message. Why is the mail being bounced in this way?