To cut a long story short, I was told by host support that I needed to use a PEAR function to send my mail, as my host has prevented nobody@localhost from sending mail, and I have no access to php.ini.
Perhaps it may well be that there's a simpler way around this (and I suspect it has something to do with smtp_library), but I'm not a programmer, and I eventually hacked and slashed my way through the Internet wilderness to a pear function... which *succeeds* in sending test messages when I access it from the browser... the feeling of joy!!! The SMTP server is on my host.
I hope to enquire - how do I now include this function into user.module so that my password creation mails, new account mails and feedback work fine? specifically this script is now sitting in webroot as Mail.php. what should I change in user_mail (which from what I can see is being accessed by feedback.module?) For e.g. for feedback, how do I make sure the feedback goes to $body below? Thanks!!
<?
include("Mail.php");
$recipients = "y@z.com";
$headers["From"] = "x@y.com";
$headers["To"] = "y@z.com";
$headers["Subject"] = "Feedback";
$body = "TEST MESSAGE!!!";
$params["host"] = "mail.y.com";
$params["port"] = "25";
$params["auth"] = true;
$params["username"] = "x@y.com";
$params["password"] = "abcdefgh";
// Create the mail object using the Mail::factory method
$mail_object =& Mail::factory("smtp", $params);