Can I tell ticket number from an email based off Ref: number?

[carlav]

Am I able to look up a ticket number based on the Ref:  number at the bottom of an email generated from a ticket?

[Saiganeshraja]

Refer here:

https://docs.servicenow.com/bundle/sandiego-servicenow-platform/page/administer/notification/concept/c_WorkingWithWatermarks.html

[carlav]

Can you use the 'Auto-numbered identifier of source record' to look up the source record somehow?