Problem logging on to incoming mail server - Outlook & webmail

[#1]

I'm a new Plusnet customer as from Monday 15th. Everything seems to be working fine except incoming email.
I've had my "Your new email address" email (yes, I can get email, it's just my incoming Plusnet email that isn't working), which contains the following lines:
Setting up your mail program
============================
To check your email, you'll need to put the following details in your mail program:
Email Username: my user name
Your password: The password you use to log in to our website
POP3 server: mail.plus.net
SMTP server: relay.plus.net
I've entered these into Outlook 2003, but when I run "Test Account Settings" it stops on the "Log onto incoming mail server (POP3)" step and prompts for username & password again (i.e. it passes the "Find incoming mail server" step). I've tried entering these details dozens of times but it still doesn't work. The same details work fine to log into the plusnet account pages however.
I also can't log in to webmail with these details either. It immediately goes to a page titled SquirrelMail:ERROR, with the message
ERROR:
ERROR: Connection dropped by IMAP server.
There are no other links on this error page.
Any ideas? I've got several other email accounts configured in Outlook & they work fine. Sending mail out via relay.plus.com also works ok, it's just the incoming mail that's causing problems.
Thank you.

[#2]

That sounds as though the mail storage hasn't been created on our side correctly. I've sent an email to the mailbox and it's now kicked it into life and should be working correctly.

[#3]

That seems to have fixed it. Thanks. 

[#4]

See the posts under "cannot access my webmail" on 29/11  .  I t seems as though something is being missed systematically when new user accounts are created.