We are using Mediawiki 1.31 and found that when $wgUserEmailUseReplyTo = true;, there were no sender's email address listed in reply-to filed, when sending email via SMTP or alternateUserMailer extensions.
In our case test, neither send mail directly through $wgSMTP (or with extensions SwiftMailer), nor by Extension:SparkPost (which send email through API system) have sender's email address in reply-to filed.
Can anyone try this function through php sendmail? We wouldn't use php sendmail as it expose server IP to public, which raise security concern.
If this is a bug, please fix it. If it's not, please forgive me.
Thank you all in advance!