Forwarding exchange mail to isp

[rkmorrow]

I have exchange 5.5 set up with Internet Mail Service pointing to an ISP. We have Global users set up, they are all pointing to their respective domains for mail, and all is fine (They have accounts on their own isp).Internal and external mail is all working. Here is the problem,We have one global user that is not on our network, but has a mail account on our ISP. She is in our Global Address Book as being part of our mail domain because she has an account with the ISP, but because she isn't on our network. We can't get the mail to go the ISP mailbox. It just hangs in the queue with the error:<recipiant@dmain.org>
[451 rejected: temporarily unable to verify sender address (try again later)<sender@domain.org>.
Anybody have any ideas on what we can do to get htis to work?

Thanks
Rkmorrow

 

[rws]

Sounds to me like the ISP is doing a reverse lookup on your domain/mail server, and you are failing. Talk to whoever is responsible for your DNS records (which might be that ISP).