set up talktalk email account

I'm trying to add the first email account to my new Mac (OS X 10.9) using the fairly self-evident 'add account' function of Mail. Firstly I select 'other account' (not Gmail, Yahoo, etc.) then I supply account name, email address (xxxx@talktalk.net) and the password all of which have worked fine on my PC for the last 5 years.

At this point I get an error message 'Can't send password securely to server' or equivalent paraphrase. The options I'm given are a) to cancel the setup or b) continue with insecure password transfer. Perhaps not surprisingly I have chosen to cancel.

The Talktalk website guides on how to do this ignore any possibility of error message - so they're not much help.

I have used the same function (Mail/Add account) entirely successfully when adding a Gmail account to the Mac. No error message. The account appears in the list. I can send and receive using it. So the Gmail server and my Mac co-operate.

The PC World guru (who earlier had sold me the Mac) suggested I should install a good Antivirus system, so I've spent more money on a McAfee package which has installed OK. No improvement in setting up emails though!

How can I make the Talktalk server and my Mac co-operate?

This is my first brush with anything carrying the Apple logo, so please spell it out to me real slowly. Thanks.