In Outlook Express look at Tools, Accounts, Mail, Properties, Servers.
Make sure that Outgoing Mail Server, My Server Requires Authentication.
Also click the Settings button and make sure that the correct logon
settings are specified

If you still have problems, you may want to record an smtp.log which
will show more details about outgoing mail.

To create an SMTP.log In OE5+, go to Tools, Options, Maintenance,
Troubleshooting, Mail
You may need to close OE after doing the send for the log to get written
to disk.
The log will be in the Store Folder which is listed in Tools, Options,
Maintenance, Store Folder.

--

Mike - http://pages.prodigy.net/michael_santovec/techhelp.htm


"Paul Lenz" wrote in message
...
I have the same problem. And I don't understand the problem
because it works with Outlook, but it does not work with
Outlook Express. All settings are the same, also port #587.
When I send a message, I get a poopup window where I
have to enter my login data. I do so and klick OK, but
after one second, the popup window appears again.

I also own the server which should accept the mails.
It's a Debian system with Exim4. In the mainlog I read:

[..] login authenticator failed for [..] : 535 Incorrect
authentication data

I have to assume there is a bug in Outlook Express because
it works with Outlook.

My system: WindowsXP (latest updates), Outlook 2000 (9.0.0.2814),
Outlook Express 6 (6.00.2900.2180).

Paul Lenz