Hi, you could use  a notification email script
email.setFrom(“AnyName <” + dot.walktoemailaddress + “>”

https://docs.servicenow.com/bundle/sandiego-servicenow-platform/page/script/server-scripting/reference/r_MailScriptAPI.html

But trying a quick test and setting a 'From' field in a notification template,
this results in the value being pushed into sys_email.user when the notification is triggered.
So perhaps you can set the value of sys_email.user during your initial sys_email record insert, using a string with the format.

'a user name <an email address>'