For converting Thunderbird emails to PST format, you can use an advanced and secure
Thunderbird Backup Tool. This utility enables you to backup and restore your Mozilla Thunderbird email client data, including emails, contacts, calendars, tasks, and settings. It also allows you to save your emails into multiple file formats such as PST, PDf, EMl, MSG, CSV, etc. With Thunderbird Backup Tool, you can also create and schedule backups, restore data to a different computer, and ensure the security and integrity of your email communications. For analyzing its performance, try its free demo version.