A few years ago Bell Canada's Sympatico ISP outsourced its email to Microsoft's Hotmail.  Sympatico users retain their @sympatico.ca email addresses, but change their pop and smtp servers to pophm.sympatico.ca and smtphm.sympatico.ca.  

I recently purchased my first Mac, and spend a long day of intense effort to get the Thunderbird email reader to work with my Sympatico email account.  I finally found a configuration that works. I offer screen shots here of the relevant Thunderbird configuration screens in hopes it may save others work that really should be unnecessary.

I have two accounts, a gmail account and a sympatico account. I got the gmail account working  immediately, but spent long hours getting the sympatico account to work. Extensive googling did not help. Extensive conversation with Sympatico technical support did not help. Much trial and error was required, with the final result being that the difficulty was that different values are required for the Connection Security field for pophm.sympatico.ca and for smtphm.sympatico.ca.

Here are screen shots of the relevant Thunderbird 3.1 configuration screens for the successful configuration running on MAC OS X 10.6.4.  The use of the alternate port, 587, for smtp, rather than the default port, 25, may be unnecessary, but I stopped as soon as I found a combination that worked. The last thing I changed was to use the different values, SSL/TLS and STARTTLS, for the Connection Security fields of , respectively, the pop and smtp server configuration screens.