Re: How I use the same Thunderbird mail account on different computers w/o "losing" i
What I always did in the past was elect one PC to be primary and one to be secondary. The secondary would be set to always leave a copy of the messages on the server. The primary would be set to leave messages for one (or two or three if your mail server admin will grant you enough space).
The downside is you always get both messages delivered to both machines. The upside is, you will generally have all your mail on both machines. Although I normally used this method with MS Outlook and Outlook express, and Eudora, it relies upon commands that are part of the POP RFC, and should work well with any decently written POP client such as Thunderbird.