I'm having a strange problem. Forum members whose email address is myname@myhost.co.uk cannot send me email through the forum by clicking the "email member" link. These people are able to register for the forums (I require email validation), and everything else appears to work. But if they try to email me, it gets bounced.
Here's a sample bounce message:
Reporting-MTA: dns;stats2.applied-innovations.com Received-From-MTA: dns;ai1022 Arrival-Date: Mon, 7 Jul 2003 19:47:48 -0400 Final-Recipient: rfc822;jeff@bigblueball.com Action: failed Status: 5.0.0 Diagnostic-Code: smtp;501 Error: user membername@somewhere.co.uk is not permitted to send mail using this server
(I changed the members email name and root domain to respect their privacy).
It works fine for everyone else. Any ideas why this would be a problem?
Perhaps these users have ended up on some kind of spam blacklist that's enforced by your ISP? Another possibility is there is some relaying configuration problem, but that kind of problem should have happened from day one.
Applied Innovations is my web host (and mail server). So no one else has this problem? If not, I guess it must have something to do with my mail server configuration, in which case I'll work with my hosting service.
That is definitely a problem with your mail server. The two possible reasons pointed out by Doug seem like the most probable causes for the problem. Do talk to your host.