
The mail() function requires an installed and working
email subsystem for sending mail. The program to be used is defined by
configuration directives in the php.ini file. A common pitfall is that
these are not set up correctly, rendering mail() inoperable. Note that
the first two directives are for use only on Windows systems; the third is for
use only on Unix-type systems.
SMTP: The host to which to connect to send mail. Can
be either...