In Windows: c:\Documents and Settings\<user name>\Application Data\Thunderbird\Profiles\<Profilename>\<Mail | ImapMail>\<mail server name>\ c:\Users\<user name>\AppData\Roaming\Thunderbird\Profiles\<Profile name>\<Mail | ImapMail>\<mail server name>\ In Mac OS X: (~ represents user's home folder): ~/Library/Thunderbird/Profiles/<Profile name>/<Mail | ImapMail>/<mail server name>/ ~/Library/Application Support/Thunderbird/Profiles/<Profile name>/<Mail | ImapMail>/<mailserver name>/ |