Php Mailer is disabled due to the use of Php Mailer to Spam. We need to the keep Server IPs clean so no has issues sending emails.
Please use SMTP for your emails. If using WordPress you can follow this guide to setup SMTP:
Create an email account in cPanel and use the details in your email script or software.
host : localhost or use mail.mydomain.com
SMTP user name : email Id created on server
SMTP password : password of the email ID.
How can I enable Php Mailer?