Check out the easy way to Export Thunderbird to MS Outlook. It can be done effectively by using manual method and if you are not much into coding then you can definitely try the third party tool for the conversion.
Cannot Import messages "The import messages from a directory" is light grey!! Are you getting this error while importing emails in Mozilla Thunderbird account? Get the solution to troubleshoot "Import All Messages from a Directory Greyed Out" Mozilla error.
In this article, both manual, as well as some alternate solutions, are described. The most convenient way to migrate from Thunderbird to Outlook 2016 is by using MBOX to Outlook Converter tool. This software helps the user in converting from Mozilla Thunderbird to Outlook PST.
Thunderbird is an email, newsgroup, news feed, and chat (XMPP, IRC, Twitter) client that supports POP and IMAP and LDAP address completion. The vanilla version is not a personal information manager, although the Mozilla Lightning extension adds PIM functionality. Thunderbird can manage multiple email, newsgroup, and news feed accounts and supports multiple identities within accounts. Features such as quick search, saved search folders, advanced message filtering, message grouping, and labels help manage and find messages. Thunderbird incorporates a Bayesian spam filter, a whitelist based on the included address book, and can also understand classifications by server-based filters such as SpamAssassin. Extensions allow the addition of features.