Updating a very old Thunderbird
 

I fix PC's in people's homes - mainly for OAPs. I have one customer who has
Thunderbird v1.0.2 and is rather reluctant to update it in case it destroys
all his emails (going back several years) and his list of email addresses.
I have been unable to find out how to back up the emails and/or the
addresses - I'm guessing things have changed slightly by v7...!

Can I do any sort of backup on the emails and addresses. Will I be able to
reload these into the latest version. Should v7 update OK without
destroying or loosing his email and addresses.

Toby