Manual:$wgEnableEmail

Email settings: $wgEnableEmail
Set to true to enable the basic e-mail features: Password reminders, etc.
Introduced in version:	1.4.0
Removed in version:	still in use
Allowed values:	(boolean)
Default value:	true

Other settings: Alphabetical | By Function

Details

Set to true to enable the basic e-mail features: Password reminders, etc. If sending e-mail on your server doesn't work, you might want to disable this.