New Message: Unexpected server response

[webmaster at userland.com]

A new message was posted:

Address: http://frontier.userland.com/discuss/msgReader$8917

By: Craig Jensen (craig at bookways.com)

When users try to join one of our frontier discussion groups they get the following error message:

Can't send mail because of an unexpected server response. I said "RCPT TO: " and the server replied "550 5.7.1 Unable to relay for user at usersdomain.com".

Membership is established in Frontier for the DG, but since the user gets the error message, the user is unaware that they are signed up.

The problem seems to be between Frontier and the mailserver.

Setup:
The company is running Back Office.

The mailserver is at the companies ISP.

Frontier 7.0b26 is running at the company using an ip address outside the Back Office firewall.

Frontier is configured with the proper mail host name.

Individuals inside the company can join and receive the memebership confirmation, but those outside the firewall, trying to join get the error message above.

Anyone got any ideas? TIA

This is a Manila site.. http://manila.userland.com/.