571 host@home.com prohibited. We do not relay

[insureme]

recently (within the last couple of weeks) a specific domain seems to be unable to send mail to my company. they are getting the following bounce back...

Original-Recipient: <user@home.com>
Action: failed
Diagnostic-Code: smtp; 571 user@home.com prohibited. We do not relay
Remote-MTA: 69.20.116.25

The identities contained have been changed for their own protection Anyway it seems that this company has tried to send messages to a few different users in my company and gotten the same response, but they are the only ones with this issue. we work with hundreds of companies so it's obviously not all e-mail affected by this. I've checked the RBL lists, and any blacklists i can find and we are not listed on any of them. I manually connected to my SMTP relay and the message is going through fine there as well. I'm not that experienced with Exchange administration so any advice would be greatly appreciated.

Thanks
Beer

 

[compuveg]

Your server's logfiles will be more conclusive than anything they get in email, but maybe not. Is that remote MTA listed your mailserver?

 

[cmeagan656]

I've checked the RBL lists, and any blacklists i can find and we are not listed on any of them.

Actually, you need to check if the sending domain is listed.

It sounds like its an issue with their e-mail/Exchange server configuration that is causing the issue since it's only that company that is having the issue.

Hope this helps.

Please help us help you. Read Tek-Tips posting polices before posting.

 

[insureme]

it's strange as the problem resolved itself a couple of days ago without me doing anything. I agree that the issue is probably on their end and not mine. by the way, the server listed is not my mail server, but that mail server of our third party filtering service, Appriver.

 

[compuveg]

That makes me think that Appriver had a tiny window where its system wasn't forwarding emails.