PHP
(a quick guide)
PHP mail requires an SMTP (simple mail transfer protocol) server to send out emails.
EIther SMTP is not properly configured. OR firewall/anti-virus is blocking mail send.
LINUX sudo apt-get install postfix (OR YUM OR RPM - Whichever is the package manager)
PHP.INI Make sure SMTP=localhost
PHP.INI For Windows only, also set sendmail_from=YOUR@EMAIL.COM
Just set the SMTP settings in php.ini accordingly. SMTP=HOST.COM smtp_port=PORT NUMBER auth_username=ID@HOST.COM auth_password=PASSWORD
Allow SMTP in Windows Firewall, Linux IPTABLES, hardware firewall.
Set exception in anti-virus.
Check spam mail folder.
Set mail.log = PATH/LOG.FILE in php.ini, and see the error messages.