A problem with Outlook Express

  Alf58 17:02 29 May 2011

Can anyone help with my Microsoft Outlook Express. Every time I try to send an email I get the following message:

An unknown error has occurred. Subject :.................. Account: 'mail.btinternet.com', Server: 'mail.btinternet.com', Protocol: SMTP, Server Response: '451 Invalid Smtp line - Should end with CRLF', Port: 25, Secure(SSL): No, Server Error: 451, Error Number: 0x800CCC6A

I have changed the subject to a row of dots for the sake of privacy but the rest of the message remains unchanged. This has started to happen within the last few weeks. At first it was occasional but now it seems to be with every email I try to send. I can receive email with no problems.

Any ideas folks?

  Alf58 17:03 29 May 2011

Sorry forgot to say I am using Win XP Professional.

  Zak 17:17 29 May 2011

Have you had a look here:

BTCare Community Forums/Broadband/BB Speed/Connection/email error "Server Response: '451 Invalid Smtp l...


Mail Server Support

  Zak 17:20 29 May 2011

Mail Server Support

[ BTCare Community Forums/Broadband/BB Speed/Connection / email error "Server Response: '451 Invalid Smtp l...


  Alf58 12:01 30 May 2011

I have looked at the thread but am unable to understand it. Also it does not reach any conclusion so I am back to square one.

The only thing I am sure of is that the error is caused by Outlook Express. I use my work laptop at home using Outlook and send and receive mail without problems.

  lotvic 13:20 30 May 2011

To shed more light on the problem, apparently "It means that the email has not been correctly composed to SMTP (Simple Mail Transfer Protocol) standards. CRLF means carriage-return-line-feed which is the so called "normal" text file line terminator in Microsoft Operating systems (only)" ClickHere and AlsoHere

  Zak 14:03 30 May 2011

Have you got any messages sitting in your Outbox in Outlook Express?

If yes delete them. It could be one rogue corrupted message causing the problem.

  Alf58 14:07 30 May 2011

Thanks to all contributors. I'll keep you posted on any changes. I will certainly delete any other suspect messages.

This thread is now locked and can not be replied to.

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