Watermarks in ServiceNow

[Nilay_Potdukhe]

 🔖Watermarks in ServiceNow

A Watermark in ServiceNow is a unique identifier automatically added to notification emails. It helps the system match inbound email responses to the correct records (such as Incidents, Problems, or Change Requests).

Watermarks are stored in the Email Watermark [sys_watermark] table.

 📧Use Cases of Watermarks

1. Default Watermark Behavior in Notification Emails

Scenario: By default, ServiceNow generates a watermark label at the bottom of each notification email. This ensures incoming replies are matched to the correct record.

• Each watermark includes a random 20‑character string to make it unique.
• The randomization reduces the chance of accidental duplication or guessing.
• Watermarks are automatically generated in base systems.

1. Watermark Format

Scenario: Understanding the structure of a watermark helps in customizing or troubleshooting.

• Always begins with Ref: (identifier).
• Default label length: 31 characters.
• Format includes:

1. Customizable prefix — default is MSG.
2. Auto‑numbered identifier — numeric string tied to the source record.
3. Underscore + random 20‑character string.

Example:
Ref: MSG12345_abcdEFGHijNOPqrstwef

1. Configuring Watermarks

Scenario: You can configure watermarks to suit organizational needs.

Options include:

• Create a custom watermark prefix for each instance (avoids cross‑instance triggers).
• Add custom prefix characters after MSG.
• Hide watermarks globally.
• Omit watermarks from individual email notifications ( inbound email actions may fail if omitted).

1. Exercise: Create a Custom Watermark Prefix

Steps to Implement:

1. Navigate to: System Definition > Number Maintenance.
2. Click New.
3. Fill in the watermark form:
• Table: Email Watermark (sys_watermark)
• Prefix: MSG (or your custom prefix)
• Number: 0
• Number of digits: 7
4. Click Submit.

1. Omit Watermark from Email Notifications

Scenario: Sometimes, you may want to omit watermarks so replies don’t link to existing records.

Steps to Implement:

1. Navigate to: System Notification > Email > Notifications.
2. Open the selected email notification.
3. Click Advanced View under Related Links.
4. In What it will contain, select Omit watermark.
5. (Optional) If you want response emails to generate new Incidents, remove the {number} variable from Subject and Message HTML fields.

[Dr Atul G- LNG]

Hi @Nilay_Potdukhe 

Adding the prefix “Blog/Article” to the title will help readers quickly understand whether the content is a question or an informational/knowledge-based article.