Outlook doing strange things to my settings

I have just set up a new website and I am trying to put in the email addresses to my Outlook. I go to Set up new mail - set up manually - put in email address and the server addresses for my host and then when I save it all it reverts to standard pop3.whatever.co.uk instead of mboxhosting.com. I keep resetting it and it keeps reverting to a setting I have never put in in the first place - really doing my head in trying to think what could be wrong