The correct answers are A and D. While the UNIX version of PHP
requires the sendmail
application (or an equivalent emulation thereof) to send mail through
an MTA, the
Windows/Novell versions communicate directly with the MTA using SMTP.
However, if
available, PHP can also be configured to use a “sendmail wrapper” to
simulate the sendmail
application on Windows/Novell, in which case all three versions of PHP
would function in
the same way. Also note that, when using the internal implementation
of mail() on
Windows/Novell environments, it is necessary to set the sendmail_from
configuration
directive, while UNIX flavours leave that task to the sendmail
application itself.