30th April 04:41
550 relaying is prohibited.
This is happening with pop3 clients? (Outlook express, eudora, outlook in
Internet Mail mode, etc)
On the server:
Check that on the IMS Routing tab you have "Allow relay" selected. Then
click on routing restrictions button, select the top check box "Only allow
hosts that authenticate" and leave the other options unchecked. If you make
any \changes, restart the IMS.
On the clients:
Make sure that the account is set up to use authentication (outlook and
express, account properties, servers tab, select the "May server requires
authentication" box) If the mailbox owners nt account isn't the same as the
mailbox alias, put the account information as
ntdomain/ntusername/mailboxalias rather than just the alias in order to pass
all the proper credentials.