Another user of Free.fr is also having the same issue. See https://support.mozilla.org/en-US/questions/1288640#answer-1316570

This cannot be a mere coincedence unless you're posting under different aliases.

This message refer the same issue as I did (I am not the author) I have no trouble using the wifi, the only issue is retriving or sending mail to or from thunderbird via imap.free.fr

Alright, let's see what your server settings are for Free.fr on Thunderbird, especially IMAP and SMTP port numbers, connection security and authentication method. Since this is happening on two devices, and one other user of the same email service provider within the same time period, my suspicions lie towards Free.fr. Something must have definitely changed on their side for this to affect multiple devices. Is your tablet also running Windows and Thunderbird?

My laptop is running Windows 10 and thunderbird 68.8.1

My system is 64 bits ans thunderbird version is : Thunderbird version 68.8.1 released May 22, 2020

Hi. Do you still have this problem? If so, go to Help > Troubleshooting Information > Copy text to clipboard then paste it into your next reply. That info will tell us more about your Thunderbird installation and spare you a bunch of technical questions.