Manual:$wgSysopEmailBans

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Email settings: $wgSysopEmailBans
Allow sysops to ban users from accessing Emailuser.
Introduced in version:	1.11.0 (r22816)
Removed in version:	still in use
Allowed Values:	(boolean)
Default Value:	true

Other settings: Alphabetical | By Function

[edit] Details

If set to true, a checkbox is enabled in Special:BlockIP that allows sysops to block a user from accessing Special:Emailuser to send e-mail to other users.