Changing User email id - effected areas

Hi there,

We've an issue where client wanted to change primary email id of all the CRM users.

say current email id is username@abcdomain.com, now it's changing to username@xyzdomain.com.

Now I want to know what are the effected areas and how can I update bulk users email ids.

Server: CRM 2016 on-premise

Please suggest.

Thanks in advance.

Kiran