Streamlining Customer Notifications into a Single Email Thread

[NaveenPrasU]

We currently send multiple email notifications to customers for a single ticket—such as when a case is created, when new comments are added, and for other updates.

Is it possible to have all these notifications grouped into a single email thread in the recipient’s inbox, instead of appearing as separate emails each time?

For example:
If a customer raises a ticket, they receive an initial “Case Created” email. Later, when comments or updates are added, those notifications could appear as replies within the same email thread—making it easier for the customer to track the entire conversation in one place.

Has anyone implemented this kind of email threading for ticket notifications? Any insights or best practices would be helpful.

[lauri457]

I think you'd need to create a br on sys_email that adds the references/in-reply-to headers to the emails. Or you just have the same subject for all emails related to a particular task and hope that the email client groups them.

Insert custom email headers into an outbound email from the ServiceNow instance - Support and Troubl...

[vaishali231]

Hey @NaveenPrasU 

Yes, this is a common requirement, but ServiceNow does not natively group multiple notifications into a single email thread. By default, each notification (case created, comments, updates) is sent as a separate email.

However, you can improve email threading behavior by aligning with how email clients (like Gmail/Outlook) group messages:

1. Keep Subject Line Consistent

Use the same subject format across all notifications

Example: Case ${number} – ${short_description}

Avoid changing prefixes like “Update”, “Comment added”, etc.

2. Use Watermark (OOB)

ServiceNow automatically adds a watermark (ref:MSG…)

This ensures replies are mapped back to the same case

Note: This helps with case association, not inbox threading

3. Configure Reply Behavior

Ensure all notifications use the same Reply-To email address

Configure inbound email actions to update the same case

4. Advanced (Customization Required)

For true email threading, you can:

Capture the initial email Message-ID

Reuse it in subsequent emails via:

In-Reply-To

References headers

This requires a custom email script or notification customization

5 . Reduce Notification Noise 

Review overlapping notifications (event-based vs condition-based)

Consider sending fewer, more meaningful updates instead of multiple emails

 Even after implementation, threading behavior ultimately depends on the recipient’s email client.

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If this response helps, please mark it as Accept as Solution and Helpful.

Doing so helps others in the community and encourages me to keep contributing.

Regards

Vaishali Singh

[NaveenPrasU]

Hi @vaishali231 ,

Thanks for your response.

We followed the steps for the email threading scenario. Here’s what we did:

• Sent an inbound email to ServiceNow, which successfully created a case.
• The system then generated and sent out a case creation email from the instance.
• We opened the email log record for the outbound email and manually updated the subject and Message-ID to match the original inbound email.
• After making these changes, we clicked the “Resend Email” option.

However, when the email is received in Outlook, it still appears as a separate email instead of being threaded with the original message.

Are we missing any steps, or is there any additional configuration required to ensure proper email threading?

Thanks in advance.

[lauri457]

You need to add it in the headers not on the sys_email record. I tested this with gmail and exact subject match and the "references" header were enough to group the received emails.

To replicate:

1. send two emails from sn (use same subject line)
2. take message id from one and add it in the headers field as references header on other sys_email record
3. resend with the modified headers
4. email should be added to thread in email client

References: <[message_id]>
<!--ex. References: <111111111.222.3333444455555@app123456.xxx123.service-now.com> -->