I am trying to run the PHP mail() function through an internal system but I keep getting the error message:
Warning: mail(): SMTP server response: 451 See http://pobox.com/~djb/docs/smtplf.html. in htmlMimeMail.php on line 671
I am using the latest vers. 1.4 of HTML Mime mail class by Richard Heyes.
Does anyone know what I should do?
