Error message appears when sending through an email program

If you immediately receive an error message when trying to send mail from an email program (Outlook Express, Windows Mail, etc), reference the chart below for a solution.

Error Message

The message could not be sent because the server rejected the sender's e-mail address.. ..'503 Authentication is requiredSMTP authentication needs to be activated in your email program settings. Click Here to verify your settings.
The connection to the server has failed. Account:'MyUserName',Server:'', Protocol: SMTP, Port: "number", Secure(SSL): No, Socket Error
An incorrect outgoing mail port may be set up in your email program. Click Here to verify your email program settings. You may also have security software (i.e.- Norton, McAfee, Trend Micro) with the firewall or email scanning features that are blocking your email. Please adjust the software to allow outgoing emails.
"Server time out" errorThis type of error can be caused by sending a large attachment that is taking too long to process (especially on a dial-up connection). Can also be caused by message corruption. Try removing any email from your outbox and resending it. If the message has an attachment, try reducing the size.
"My.outgoing.server" can't be foundThis error indicates that your outgoing server can not be located on the Internet. Insure your connection is still active by opening a web page in a web browser (i.e.- Internet Explorer). Also, Click Here to verify you are using the correct outgoing mail