We are having a problem sending E-Mail that started two days ago.
Background – We are using Windows 2003 Small Business Server with Exchange. Each User is using Outlook 2003 as their E-Mail Program. We do not host our own E-Mail.
Problem – When we send an E-Mail, it immediately comes back as “undeliverable” with the following message:
550 Not Local Host
(domain) not a gateway
We have no problem receiving E-Mail. We have found that is we Log Into your Outlook Account on the Server that there is no problem sending E-Mail. We have tried removing and re-installing Outlook 2003 which seems to initially solve the problem, but it later re-occurs. We were thinking that this is an Outlook problem until I rembered that we still had one user using Outlook Express. They get the same problem.
I have reviewed the Event Log and there are no error messages that indicate what the problem is.
Any ideas?