SharePoint 2016 User information list is not updated from UserProfile
In SharePoint 2016 the User information list in sites is not updated from the UserProfiles. The sync job is not working the right way. Probably a bug in SharePoint.
In the user information list or table you can see wrong email addresses and when you share a document with that person in the site you get a bounced email back.
Workaround: trigger an update by giving a user temp. permission on the site or use powershell: Set-SPUser -SyncFromAD You can schedule this for every user on every site. I can share this script when you need it.
See also this discussion on TechNet:
https://social.technet.microsoft.com/Forums/en-US/42abec03-798f-4ccd-a80f-cd5077e72de2/sharepoint-2016-strange-behavior-user-information-list?forum=SharePointMigrationTool&prof=required