Since you can't send and receive conventional (i.e. SMTP & POP3) email with Internet Explorer (other than indirectly, via a web site), I'm going to assume that your question refers to Outlook Express, rather than to Internet Explorer.
Outlook Express has a nasty habit of losing (or mixing up) the settings it requires to send and receive email. To be fair to Microsoft, the problem is often related to anti-virus software which has to make changes to these settings in order to scan mail.
Go to Tools > Accounts.
Click on the 'Mail' tab.
If you've only got one email account it will probably already be highlighted. If not, click on the relevant account to highlight it.
Click 'Properties'
Select the 'Servers' tab
Check that the incoming mail server is shown as pop.orangehome.co.uk
Check that the outgoing mail server is shown as smtp.orangehome.co.uk
Check that your username is correctly filled in.
Delete and retype your (asterisked) password.
Check that there's a tick alongside 'Remember password'.
Click 'Apply', 'OK' and 'Close'
If that doesn't work, start as above but instead of selecting 'Properties', click 'Remove'. When asked to confirm that you wish to delete your mail account, click to do so. Then click Add>Mail and set up the account again, by simply following the prompts.
Chris