Copy the contents of the entire profile folder and all subfolders from the source machine to the destination.

Locate the profile folder on the source machine.

Erase the contents of the profile folder on the destination machine.

Locate the profile folder on the destination machine.

Run it once on the destination machine, configure nothing, and exit.

Install Thunderbird on the destination machine (the machine on which you want to have your email).

Close Thunderbird on the source machine (the machine on which you currently have your email).This makes copying your Thunderbird-based email from one machine to another a simple process. Your profile folder has everything: mail, mail folders, email accounts, contacts, installed extensions, and so on. Thunderbird uses what it calls “profiles” to locate all of the information associated with your email. All you need do to move your Thunderbird email is to locate the profile on the old machine and copy it in its entirety to the profile location on the new machine. Thunderbird stores all your information in what it calls a “profile” - a folder that contains everything.

Old thunderbird