Download and install Mac OLM to Thunderbird Tool- it is one of the best conversion solution. It instantly backup OLM file to Thunderbird with complete details. The app has very simple GUI interface so you can effortlessly backup OLM file to Thunderbird without technical support or help. One can also try a free trial version of this utility to backup OLM file to Thunderbird profile. It provides free conversion of up to 25 OLM files to Thunderbird. With a license key, users are allowed to convert unlimited OLM emails to Thunderbird in a single round.