How DID I import a single (also need multiple) .EML file into TB 115.10 -- and now can't duplicate (no extension needed)?

After wasting hours trying “this and that” – I did successfully "import" (not in the “import” menu) a single .EML (text) email file into my TB 115.10 e-client? I can’t remember how – and can’t duplicate it. Yes, I know there’s an “extension” to do this, but if I did it only with TB 115.10 – why deal with the paranoia of permissions (must have access to everything)? I need to “move” about 4000 emails from an ancient ISP (still used, too) into my TB 115.10 e-client – to then move to ”Folders” and then archive off-line. I can download emails (to my folder) from the ISP only individually as .EML files – and did get one successfully into TB (it reads [looks about the same] as an email “retrieved” by TB). I can only “download” individual ISP emails (their rules, programming) so, hoping to set up a macro to “download” about 100 per day. My ISP inbox is almost full every day with new emails that must be deleted or “moved” due to new emails arriving every day. Any ideas – or better still step by step suggestions? Responses in Spanish are fine – French or Portuguese workable. Dru <redacted>@OneImageDru.com