Best practices for monitoring email
We have multiple application servers & each one relays the emails we generate (via SMTP) to our email gateway that is responsible for sending them out the door. I currently monitor the SMTP service to make sure it's running but it's possible there could be some network problem somewhere such that our SMTP services are running but the emails aren't leaving our application servers. What method would you recommend to trap that? For security purposes I don't have access to the gateway server.