Aryson Thunderbird Backup Tool is a reliable and safe software to backup and migrate Thunderbird Mails. It helps those who are looking for an easy way to migrate their Thunderbird Mail into different file formats and email clients. The software allows users to migrate their Thunderbird Mail data files without any data loss. Also, the software allows exporting specific files from a particular time period. Users can easily delete or remove duplicate emails from their data items. Aryson Thunderbird Backup Software offers a demo version software that allows the export of 50 email items per folder from Thunderbird Mail to the other file format or email client.
Source: http://www.arysontechnologies.com/thunderbird-backup/