How to send outbound emails as a reply in the same email thread?

[TanyapongS]

Hi everyone,

I am working on an outbound email integration where the system sends an initial email notification to an external vendor system when a record is created. Later, when the same record is updated, we need to send additional update notifications.

The requirement is that the update emails should appear in the same email conversation/thread as the original email, rather than creating a new email thread each time.

Currently, the emails are being sent using the Send Email action in Flow Designer. I understand ServiceNow supports email watermarking for tracking replies, but I would like to confirm the recommended approach for ensuring outbound emails are treated as a continuation of the original email thread.

A few questions:

1. What is the recommended way to send a follow-up email from Flow Designer so that it remains in the same email thread as the initial outbound email?

2. Is enabling Include Watermark and forcing the subject to be the same as the first initial email on the Send Email action sufficient for this scenario, or do we need to explicitly set any email headers such as:

   • In-Reply-To
   • References

Any guidance would be appreciated.

Thanks!

[JenniferRah]

The watermark is really for ServiceNow to handle the replies to the emails so that comments will be added to the appropriate record. 

Are you wanting the second email to show in the user's inbox as a reply to the original email? I'm not sure how to accomplish that or if it's even possible.

If you just want both emails to show in the activity stream of the record, that's accomplished by adding the same record in the Flow's Send Email actions as the Target Record.