The mail() function allows you to send mail.
No external libraries are needed to build this extension.
There is no installation needed to use these functions; they are part of the PHP core.
The behaviour of these functions is affected by settings in php.ini.
Table 1. Mail configuration options
For further details and definition of the PHP_INI_* constants see ini_set()
Here is a short explanation of the configuration directives.
Used under Windows only: DNS name or IP address of the SMTP server PHP should use for mail sent with the mail() function.
Used under Windows only: Number of the port to connect to the server specified with the SMTP setting when sending mail with mail(); defaults to 25. Only available since PHP 4.3.0.
Which "From:" mail address should be used in mail sent from PHP under Windows.
Where the sendmail program can be found, usually /usr/sbin/sendmail or /usr/lib/sendmail. configure does an honest attempt of locating this one for you and set a default, but if it fails, you can set it here.
Systems not using sendmail should set this directive to the sendmail wrapper/replacement their mail system offers, if any. For example, Qmail users can normally set it to /var/qmail/bin/sendmail or
qmail-inject does not require any option to process mail correctly.
This extension has no resource types defined.
This extension has no constants defined.