Getting Proofpoint SMTP Relay Working with ServiceNow

[sgrison]

Email is one of those integrations that looks simple on paper until you're knee-deep in bounced notifications and nobody can figure out where the message died.

Email integration is one of the first things stakeholders notice when it breaks and one of the last things that gets properly tested. When your organization routes outbound mail through Proofpoint, getting the configuration right upfront saves a lot of pain later.

The first step, and one that's easy to overlook, is getting your ServiceNow instance IP addresses whitelisted on the Proofpoint side. Before any configuration happens in ServiceNow, provide your Proofpoint team with the outbound IP addresses for each of your instances. If you're running multiple environments -- DEV, TEST, UAT, PROD - each may have a different IP and all of them need to be accounted for. Skipping this means your relay authentication will fail before it even gets started.

Next, confirm your SMTP relay hostname and port. Proofpoint typically exposes a relay endpoint along the lines of smtp-us.ser.proofpoint.com on port 587 with TLS. Get that confirmed by your email team early - don't assume it's the same across environments.

The third thing is your service account. Proofpoint relay authentication requires a valid sending account, and that account needs to be whitelisted on the Proofpoint side. In my experience, this step gets missed and you end up with silent failures where ServiceNow thinks the email sent but Proofpoint dropped it. Always confirm the service account with your email admin before testing.

Once configured under System Properties > Email, test with a real notification and validate delivery end to end - not just that ServiceNow shows it as sent.

Finally, make sure your DEV and TEST instances are either pointing at a sandboxed relay or have outbound email disabled entirely. The last thing you want is test notifications landing in real inboxes.

Get these fundamentals right upfront and email will be one less thing keeping you up the night before go-live.