There is some allowance, but I agree it can be challenging. try this:

1. enter one good email address with fields you normally use into thunderbird' addressbook
2. click the three dots to the right of addressbook name and export in csv format. This will be your template
3. open that export into a spreadsheet program
4. note the top row. this shows the columns as thunderbird expects them to be
5. open your exported outlook csv into spreadsheet and adjust columns to match, including the top row.
6. save as csv
7. import into thunderbird

I am not going to use excel to remap. Thunderbird needs to allow the remap on THUNDerbird. I saw it work and all I need is for the remap to be allowed on the Thunderbird import!!!

Allow the mapping page as a option help Please. or at least explain why it was disallowed since I did see it on an import but I didn't have a proper file to import at that time.