Problem with a Plusnet Alias email

[#1]

Hello All,
Just wondered if anybody can throw any light on this problem?
I am using outlook 2013 and every other email is working fine apart from this one
It logs in to the  pop server ok but will not send a test email. Here is the error what it shows
Send test e-mail message: Cannot send the message. Verify the e-mail address in your account properties.  The server responded: 550
> sender rejected - invalid domain (no MX or A record)
Reagrds
jim:green email removed mod:end

[#2]

These are the settings I have in Outlook 2003
Does that help

[#3]

Thanks for your reply, That it was I have in all my setting for the others, So I am not sure what the problem is hence my thread for any help/advice, I have asked a question with support but just thought I would try here as well.
Ok, found the problem.... TYPO... Thanks for your help