Manual:$wgEnotifUseJobQ

Email notification (Enotif) settings: $wgEnotifUseJobQ
Send mails via the job queue.
Introduced in version:1.11.0 (r21898)
Removed in version:1.27.0 (Gerrit change 265682; git #334e8f8f)
Allowed values:(boolean)
Default value:false

Details

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Since MediaWiki 1.27, the job queue is always used to send email.

If true, send mails via the job queue.

If you are setting this value to true, check that $wgServer is set explicitly in your LocalSettings.php , as the usual $_SERVER method for detecting the wiki URL will not work if the job queue is run from a cron script.