If you want to import Thunderbird mail to Office 365, download MailsDaddy Thunderbird to Office 365 migration tool. It easily exports single or multiple Thunderbird MBOX & Maildir files to Office 365 mailbox. This successful tool also migrates filter and selective emails from Thunderbird to Office 365 with data properties ( bcc, cc, from, date, and attachments). Users may also try the free trial, which allows them to export the first 20 Thunderbird emails to Office 365.
The software supports all Windows and Thunderbird versions as well as is capable to import data into default and In-place archive mailbox.