Send an SMTP SAML command.
Starts a mail transaction from the email address specified in $from. Returns true if successful or false otherwise. If True the mail transaction is started and then one or more recipient commands may be called followed by a data command. This command will send the message to the users terminal if they are logged in and send them an email. Implements rfc 821: SAML
(string) (Required) The address the message is from