I have a registration form that sends e-mail to the registrant and a registrar. The form worked a year ago and it's time to put the form up again and mail (via PHP's mail function) is only being received intermittently.
I've also tried sending e-mail from the command line and mailq shows it leaves the local server but, it never seems to make it to the recipient.
I've seen a post making reference needing to use authentication with SMTP now.
Since mail has been received intermittently, I'm assuming the PHP is still good. Has the SMTP setup changed?!?