Manual:$wgPasswordSenderName/en

Details
Sender name in emails from the password reminder or the email notification system.

See Manual:$wgPasswordSender#1.17 to 1.22 for more information about this setting.

Effectively removed in 1.23 (although the value is still present for use by extensions). To set the sender name for email notifications, edit the page MediaWiki:Emailsender on the wiki (default value is ).