Free/thunderbird email reception

Hello, following my last question (FREEMAIL blocked) I still have a problem receiving certain emails, including those from the forum. For "le bon coin," I reported it to them, and I do receive their emails, but not the code intended to change my password since it is not recognized (even though I am sure I am typing the correct one).

My daily newspaper used to send me an email every evening to let me know that the next day's newspaper was online. That one is no longer arriving either. I reported the issue to them and received an acknowledgment email. I am waiting for their response.

I assume the problem is on my end, but which one? PC? Thunderbird? Freemail?

If anyone has an idea...... I don’t know what to do anymore. Have a good day and happy holidays to everyone.