Exchange 2003 Remote host said: 550 5.1.1 User unknown

Refer http://technet.microsoft.com/en-us/library/bb123637(EXCHG.65).aspx and see if you can set up the exchange server properly

Hi upu007
My connection seems to be set up correctly.  I can telnet in on port 25 but when I send an email I get the error message.
Any further thoughts?
Greg

Hi Greg,

On the MS Exchage site, locate SMTP Diag.

Are you asking a question about an external server or your own server?

My own server

So you can receive but not send. Is this for all domains or just this one domain?

It seems to be just the one domain

Can you telnet this outside domain and see if it accepts an email from your domain? The error message that you mentioned, what is that? is it the error that you get when you try to transmit a test message using telnet?

How to Telnet - http://www.yuki-onna.co.uk/email/smtp.html (just in case)

Have you set up your DNS records properly and do you have SPF records in place?

Sorry about the delay been crook.
Mail works fine in other direction.
thank you very much for your help
Greg

Not a problem.
Other direction is incoming email right? What I meant was whether you could use TELNET to send an email out to this domain as if you are sending it yourself. There is a possibility that this will give another error which will help us.

Hi and thanks
I am geting a bit comfused about which domailis which, I will try and clarify.
Problem domain with exchange server
External domain POP3
Problem domain a cannot receive emails from Extrnal domain (but can receive from other domains)
External domain can receive emails form problem domain,
Greg

Will do but they can't do it till tomorrow
Greg

Thanks for your help it just started working