I am the same. I do not feel comfortable handing the passwords of my email accounts over to a 3rd party.Old thread, but since it has been resurrected... I use Thunderbird because I like having local copies of all my emails rather than leaving their preservation in the hands of a 3rd party. I've been using local email clients for a long time, with the oldest email I still have archived dated 2000-01-01.
I have 4 email addresses, but 2 are old and unused, so I really just have 1 personal and 1 for work. However I own my own domain and run my own email server, so I can create as many as I want, and often do for one-off use.