Programmer required

A PHP programmer is required to write a script for sending mail from a PHP site,
so that emails sent from the site reach @gmail.com, @yandex.ru and @mail.ru
at the moment, when using the mail command (PHP), emails reach @yandex.ru sometimes to @mail.ru and do not reach @gmail.com

!!! It is necessary to write an example script in PHP so that the letters reach all 3 mailboxes!