CAUSE: The mail servers are set to POP before SMTP as a security measure to prevent SPAM. The mail server collects the TCP/IP address during authentication with the POP server, and then permits SMTP relaying from that TCP/IP address for a short period of time.

This means that incoming mail MUST be checked before mail is allowed to be sent. If setting an E-mail client (like Microsoft® Outlook) to check mail regularly,outgoing mail may sit in the Outbox until the incoming mail is checked again.

If only checking mail when initially opening the E-mail client,a Send/Receive will need to be forced before the outgoing mail can be sent.
IfE-mail is not checked within 30 minutes,an "Error 554: Relay Access Denied" error may be received.

SOLUTION: Quick Fix
1. Move anything in the Outbox to the Drafts folder.
2. With nothing in Outbox, click Send/Receive.
3. After a successful Send/Receive, try sending an E-mail from the Drafts folder.

Long Term Fix (in Microsoft® Outlook)
1. In Microsoft® Outlook, go to "Tools" then "Email Accounts".
2. Click "View or change existing E-mail account", then click "Next".
3. Select the account, then click "Change".
4. Click "More Settings".
5. Click the tab labeled "Outgoing Server".
6. Select "My outgoing server (SMTP) requires authentication", then select "Log on to incoming mail server before sending mail" at the bottom.
7. Click "OK".
8. Click "Next".
9. Click "Finish".