We are sorry to inform you that it's not possible to change the mail address of the user. It's recommended to create a new user, copy mail from the existing user to the new user, and delete the old user.


Or you can set the new email ID as alias ID of existing email ID. This can be done through Admin Panel.

Refer below article:

https://helpcenter.mithi.com/en/support/solutions/articles/48001276554-how-to-add-an-alias-id-and-its-usage


The mail address is the primary identity of the user. So it cannot be changed.