Permission denied to external address

[Zracer03]

We have a customer we deal with that we simply can not send mail to. We have no issues with any other email domain, but this one. When we send them email, to any of their address at their site, we get a bounce back. with this message at the bottom..

You do not have permission to send to this recipient. For assistance, contact your system administrator.

<servername.corp.domain.com #5.7.1 smtp;550 5.7.1 Access denied>

In the message above, it lists our server and domain. I have spoken with their IT guy, and he insists our domain isn't blocked and their our no issues on his end, yet this is the only company we have problems with. We do not filter external email, in any way shape or form. The only thing we do happen to do, is limit our users who can send external mail. On the SMTP connecter, by default, we reject everyone, except those listed in a group we specify, which would be below it. We have even set the server to allow everyone, just to eliminate possibilities, but we still couldnt send to only that company. If I use my Yahoo account and send to them, it goes through fine. Their IT guy basically told us there is nothing he can do. I can not see how it is on our end, and if it is, i'd love to know how to fix it. Any ideas? thanks

 

[Davetoo]

The issue is on the recipients end, not on yours. Their IT guy is missing something.

I'm Certifiable, not certified.
It just means my answers are from experience, not a book.

 

[Zracer03]

Thanks.. I'm glad someone here feels the same as I do. I wish I could get that through their head.