Since I am a real master at forgiving things I am writing this one down. PHP mail function relies on sendmail but SELinux by default block webservers from sending emails, the usual error that pop-out is: cat /var/log/maillog"> --- sendmail[16328]: NOQUEUE: SYSERR(nginx): /etc/mail/sendmail.cf: line 0: cannot open: Permission denied Allow webservers to send email is as easy as editing the appropriate SELinux boolean: setsebool -P httpd_can_sendmail 1 Use sestatus to check SELinux booleans: …

The whole web is full of pseudo guides on how to properly - that is the key word here - configure Nginx to perform caching alongside with PHP-FPM, but every single one of them fails to mention some minor steps resulting in a borked half functioning implementation. For example, not a single one mention the necessity to edit /etc/php.ini and set session.use_cookies to 0. Too bad that without doing so caching with WordPress in combination with certain plugins or themes (for example MainWP or Enfold theme) is completely not working; the following headers get added to every HTTP response: …