My Mediawiki installation (1.28.0, PHP 7.0.13) doesn't send any email and yet there is no error reported. I checked using Special:EmailUser page.
What I have tryed:
1) Command line SendMail can send email without problem.
2) A simple PHP script to send a mail using PHP's mail() function. It works.
3) I have turned PHP mail log. There is a normal log line for each Mediawiki email "sent", but nothing is actually sent.
Additional info:
PHP is configured (correctly since it works) to send email using Linux SendMail. MediaWiki is not configured to use direct SMTP.
Any suggestion apreciated. Thanks.