[SOLVED] Web Server not sending emails to external addresses

Melnape · 08-12-2015, 02:41 AM

We have a Linux Web Server and a Windows Mail Server (Exchange 2010). When sending email from the Linux server, emails to internal addresses on the domain work correctly, however emails to external addresses receive the error message Response: 550 5.1.0 Sender rejected. IB506.

Ser Olmy · 08-12-2015, 08:14 PM

Are you using the Exchange Server as a Smart Host? If so, make sure you configure Exchange to allow relaying from the IP address of the Linux web server.

If you need further assistance, it would be helpful if you could provide some details about your setup, like which Linux distribution you're using, how your Linux MTA (sendmail, Postfix, something else?) is configured, and exactly where you see the 550 error message.