I'm having problems sending emails using Outlook 2007

When you send an email, this action often needs to be authenticated by the mail server.  Essentially, it is checking that you are a valid mail user, and you are allowed to send emails.

When you sign in to your email account, your username and password authenticates your use of the server.  This process opens a timeframe of authentication for the use of that server.  Rather than work through the ?Sending Email Issues? guide, in Outlook 2007 you can select an option that forces your Outlook to check for incoming mail first, and then send emails.  When you have not selected this option, it is common to receive the following error:

553 sorry, that domain isn?t in my list of allowed rcpthosts (#5.7.1)

To enable this option, go to ?Tools? ? ?Account Settings? ? select your email account and click on ?Change? ? ?More Settings? ? ?Outgoing Server?.  Select ?My outgoing server (SMTP) requires authentication?, and then check ?Log on to incoming mail server before sending mail?.  Click on ?OK?, ?Next? and ?Finish?, ?Close?, and you will now be able to send mail without any errors.

If you are still having sending mail issues, please consult the ?Sending Email Issues? guide.