Hi I have hosted my website on digital ocean server. but after sign up some users (mail.com and arvixe.com) are not receiving activation mail from my website. Actually I am sending mails from with php function called mail http://php.net/manual/en/function.mail.php
Note : users of gmail, hotmail, rediffmail, yahoomail receiving activation mail from my website.
These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.