Cannot send via SMTP in Outlook, but work with Outlook Express

[Anna Patzer]

Hello All
I am having problems configuring my Outlook to work with POP3-SMTP
I have set up SMTP authentication on the server, and I can successfully send
externally using Outlook express. However, when I set up Outlook the same way
I get the following error message: 550 5.7.1 Unable to relay for [email
address]
I even tried importing the Outlook Express settings into Outlook, but I
still get the same error.
Can Anyone shed any light on this?

Thanks!

 

[Anna Patzer]

Nevermind, I figured out the problem... I had unticked the basic
Authentication... I realise that sending the passwords accross in plain text
is not good, but until my employer gets an SSL certificate so that I can
enable RPC over HTTP, that's what I'm stuck with!