SSIS Send Mail – Mailbox Unavailable

Scenario:

· new development SQL Server 2005 server;

· project to upgrade existing DTS packages to SSIS;

· to notify users of failure, we wanted to use Send Mail task

· We got the following error:

Mailbox unavailable. The server response was: 5.7.1 Unable to relay for myemail@mydomain.com).

This was a new server and network administrators assured me that I am using right login and server (and that I do not need to specify username and password for SMTP server).

To take SSIS out of equation, I tried to configure Database Mail and send test email, but I got the same result. After a while I realized that we should use Windows Authentication using Database Engine Service Credentials instead of Anonymous Authentication.

I came back to my SSIS package and set SMTP connection to use Windows Authentication and then everything was working.

I assume that same error can be encountered when you do not have the right name of the account, name of the server…