Cannot send e-mail in windows live mail

[roycampbell]

Hi all, first time user here. I've searched a fair bit but not found an answer, lots of similar issues but...

Yeaterday, with no changes being made to anything e-mail related or other wise, my e-mails stopped being sent (new or replies), the error below describes.

All the settings in the accounts properties are the same as was being used previously (since I got windows 7 last year) The outgoing mail server "server requires authentication" box is checked as is "use same setting as my incoming server". I clear out my in box regularly 60-70 e-mails currently)

The message could not be sent because the server rejected the sender's email address. The sender's email address was <Edited>
Subject 'Re: test'
Server Error: 550
Server Response: 550 Not permitted
Server: 'mail.btconnect.com'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 25
Secure(SSL): No

I'm flummoxed, heres hoping

Regards

Roy

[roycampbell]

Now today, it seems I'm not receiving e-mails either.

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 User unknown  (state 14).

MIME-Version: 1.0
Received: by 10.223.1.197 with SMTP id 5mr245187fag.53.1305141315346; Wed, 11
 May 2011 12:15:15 -0700 (PDT)
Received: by 10.223.89.134 with HTTP; Wed, 11 May 2011 12:15:15 -0700 (PDT)
Date: Wed, 11 May 2011 20:15:15 +0100
Message-ID: <Edited>

Subject: test
From: <Edited>

To: <Edited>

Content-Type: multipart/alternative; boundary=20cf3054a7af7ba2c904a304e488

HELP

[JohnE]

I am sorry to hear that you are having difficulty with sending e-mail, roycampbell.  I strongly suggest that you contact the helpdesk: Contact Us  Who will be able to help.

The error, 0x800CCC78 usually indicates a problem with the e-mail address.

[imadahmad]

hi I can not send an email from my window live mail i got this error

The message could not be sent. The authentication setting might not be correct for your outgoing e-mail [SMTP] server. For help solving this problem, go to Help, search for "Troubleshoot Windows Mail", and read the "I'm having problems sending e-mail" section. If you need help determining the proper server settings, please contact your e-mail service provider.

The rejected e-mail address was 'imadahmad@btconnect.com'. Subject 'Electronic Ticket Receipt - AZRAMRS SAEED Travel Date: Wednesday 12 December 2012', Account: 'Imad Ahmad - BT Connect email account', Server: 'smtp.btconnect.com', Protocol: SMTP, Server Response: '550 Not permitted ', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC78

[valj46]

Sky will not let me use their e.mail address ,how do i get an e.mail account with b.t

[treetops]

unable to send mail from e mail address

Error 0x80004005  OR  4003   -  changes daily

Protocol  SMTP

Port  25

been like this for 4 weeks !!!!

have another address - different server - which I use to send,  but receive on bt address

HELP

PF