Exchange problem - Error 5550 "5.7.1 Unable to relay for...

[PS]

Can send email through our internal Exchange server to
others in the same domain. But can not send email outside
our domain. I get the following error message.

Error
A message in your Outbox could not be sent using account
"xxxx". The server did not recognize the recipients or the
server fefuses to allow you to send mail.

Explanation
5.7.1 Unable to relay for 'email address'.

Does our Exchange server have to allow relay from a Mac
running Entourage X v 10.1.4? For obvious reasons we do
not allow relaying from our client PC's. The MS Outlook
boxes work fine. Our first Entourage X Mac does not. Old
macs running Outlook for Macs runs fine.

Please help.

 

[Mickey Stevens]

Make sure the server is set up to allow SMTP access. Because Outlook 2001
for Mac and Outlook for Windows send mail via MAPI, if it is not currently
enabled you would not notice it on those machines.

If you still have problems, you might also want to try toggling some options
in your Exchange account setttings. Go to Tools -> Accounts, open your
Exchange account, click the "Mail" tab, and then click the "Advanced Sending
Options" button. You should try toggling the "SMTP server requires
authentication" option, as well as the "SSL" one if you want to experiment
further.