Importing mail archive into Thuderbird

[Robert Moskowitz]

I am asking this here, as my system is F20 with Thunderbird 24.7.0.

I have downloaded an month's archived messages for Centos-arm and want 
to import them into Thunderbird where I could then respond to them more 
easily.

I tried the Tools>Import but when I select email, nothing is listed in 
the dialog box.  So how might I do the import?  Where might i find 
instructions?