Setting up an email server on the DS409 (DSM 4.2)

[UpTooL8]

I'm trying to set upt the email server on my DS409 (DSM 4.2) and everything seems to be in order.  I can connect to the server via Outlook with IMAP but I must use an admin user ID and password to it.  I can send out emails no problem but when I reply or send a new message to the server I get;

The error that the other server returned was:
554 5.7.1 <xxx@xxx.net>: Relay access denied

I don't know why this is happening.  Please provide some insight.

Thanks in advance.

[kohdee]

5.7.1 means you can't use that box as a relay based on your settings.

Maybe with a DSM 4.2 box, you should check out the Synology forums?