NOTE : Remember to enable "Outgoing Mail Server Authentication" in your e-mail program. With out enabling this setting you will not be able to send e-mail from our servers.

In outlook Express you can enable this under (Tools > Accounts > YOUR MAIL ACCOUNT > properties > Servers > Outgoing Mail Server > (enable) My server requires authentication)

If you have domain name pointers, you must use your primary domain name, not any domain pointers. Using a domain name pointer as your SMTP server will not work and you will encounter problems sending email from your account.