Manual:$wgEnotifFromEditor

Details
If true, sets the From: address of email notification as the email address of the user who made the edit. Otherwise, the email notification appears to be sent from the wiki server administration address ( ).

If the user who made the edit has not provided an email address, or has not allowed their address to be disclosed, the email will appear to come from  .

You need to set   to true for this setting to take effect.

If   is false, this setting is ignored.