Thunderbird to Outlook migration was easy.
Ignacio Gaxiola
I had to use thunderbird portable for a couple of weeks as my principal computer was down. I reinstalled everything and I had to migrate my emails in that client to my outlook installation. I use 7 email accounts personal/business, so using Outlook Import Wizard was an option, I needed to have them all together. So, I exported thunderbird’s emails to .eml and then import them to Outlook.