>Thats part of the problem. There is no error message. Just a popup in
>Outlook express or any other email client that says: "Error sending
>message" Period. Nothing, nada, not even a bounce message.
Somewhere on that popup for Outlook Express, there's a way to get more
info (either a button marked "More Info" or a little question mark in the
lower right hand corner). If you click on that, you'll get the text of
either what the server said (i.e., "550 relaying denied") or of what the
client thought ("Unable to resolve mailhost.wherever.net"). You need to
find something like that. Or you need to reproduce it in a way that lets
you correlate with your server log files.
Outlook and OE are both pretty bad about this - if there's a problem
(like incorrect local user names) in the mail message, they'll leave it in
the outbox and keep trying rather than bounce it. You need to find that
"more info" to get further.
