Here's a short explanation of
the configuration directives.
mail.add_x_headerbool
Add X-PHP-Originating-Script that will include UID of
the script followed by the filename.
mail.logstring
The path to a log file that will log all mail calls.
Log entries include the full path of the script, line number,
To address and headers.
SMTPstring
Used under Windows only: host name or IP address of the SMTP server PHP
should use for mail sent with the mail function.
smtp_portint
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.
sendmail_fromstring
Which "From:" mail address should be used in mail sent from
PHP under Windows.
This directive also sets the "Return-Path:" header.
sendmail_pathstring
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
/var/qmail/bin/qmail-inject.
qmail-inject does not require any option to
process mail correctly.
This directive works also under Windows. If set, smtp,
smtp_port and sendmail_from are
ignored and the specified command is executed.