So I have two SEPM servers that the email settings are configured that same exact way. They have the localhost name as the server address and use port 25. Why can one send email alerts and the other cannot? They are sending to the same email address. They are on two separate networks not connected in anyway shape or form. The server which SEPM lives on does not have any type of email clients to email servers that it can talk to because the email is hosted by office 365 so it has nothing to do with the network. There are no firewalls set up on the server that cannot send emails. The Symantec endpoint client is not installed on the one that cannot send emails. Both are being pointed by hostname not ip address.
I can send test messages with the one that work with these settings to outside the network with no issue as well and I get them as well. But the other cannot send test messages. It just fails.
What could it be?