550 Unable to relay...user unknown

[scriptfish]

I know next to nothing about Exchange, I'm just a Unix account, trying to send mail out to an external address using an Exchange server as a relay, and sendmail gets this error immediately from Exchange. Now, the Exchange admins (who are themselves new to Exchange) are telling me that they think they have STMP relaying turned on, and they don't know why the Exchange server is bouncing the mail. Is there something they could be missing? Perhaps some sort of security options that, by default, might be locking down relaying somehow? Could it be that their Exchange server isn't resolving addresses correctly (although I'm guessing that since the error is returned so quickly, it's not a DNS issue)? The admins, like I say, are new to Exchange and mail concepts generally, I think, and could use any helpful hints I can come up with. They just switched over from Groupwise (which used to relay the same mail just fine) .

What should I have them check?

 

[dredogg]

Realying is open by default with Exch5.5. So your Mail admins changed it, so they know something about exchange, or someone set it up for them...

I think to fix your problem, they need to play with the "Internet Mail Service Properties" sheet (under Connections), and click on the Routing tab.

I think they just have to click on Add... right there, and add your domain, but there might be more to it.

I've never done that before, so I can't say 100%..... Maybe someone else in the forum can chime in?