Using SSL/TLS with POP3/IMAP and SMTP is an excellent idea.
To set it up do the following:
1) Use the server's host-name for the email server host-name.
Example: If your web hosting accounts are on the 'Penguin' server then use penguin.dnsuk.co.uk instead of mail.yourdomain.co.uk
2) Turn on SMTP Authentication (My outgoing server requires authentication in Outlook Express) when you enable SSL.
3) Accept the certificate when you see the warnings the first time.