I am trying to setup a SMTP server (email receipts for our commerce site), and I receive a 550 error. Below is what I grabbed from telnet:
rcpt to: <firstname.lastname@example.org>
550 5.7.1 Unable to relay for email@example.com
When I authenticate, it sends fine. However, the components for the site (SendSMTP) cannot authenticate. In terms of security, I restricted the server to only accept emails from its own ip, perform r-dns on all attempts to use the server, and blocked off port 25 at the router (incoming connections). Hopefully that will keep the spammers at bay.
Unfortunately, I cannot seem to get the server to send its test message, much less any emails. The Commerce App is running on high-levels accounts, so there shouldn't be any problems. Any ideas what is going on here? Perhaps I forgot to configure something.
Oh yeah, this server is running on IIS 6.0, on Windows 2003 EE.