Failed to notify 'operator' via email.

I had to shuffle some SQL Servers around along with SQL Jobs. Our SMTP server has changed as well so I had to run through all SQL Jobs to make sure notifications are properly set. As I'm testing some notifications I realize that e-mails are not going through. What can be wrong?

• Database mail enabled.
• Test e-mail goes through.
• Operator set up correctly.
• Notification is set for job completion so it should go through no matter what.

However, in the History of the SQL Job, there is the following note: Failed to notify 'operator' via email.

I vaguely remember this error from the last time I was setting up a new SQL Server but I could not find my notes as to what the fix was. So I do my usual search and I find the solution.

Solution: Go to SQL Agent Properies>Alert System and enable the mail profile and restart SQL Agent.