Organisation will be for the account you created and this information will be included in the headers when you send emails to others. So in your case, it would show in the 'full headers' view of your Sent emails. If people are able to add the same to their mail account and send to you, then it would be seen in the 'Full header' view when you select an email to read.

There is an addon which would allow you to create a column for that 'Organisation' header, but it may not as yet be working in the latest Thunderbird. This link is to the version that works for 68*, but as you can see they are working on one to be compatible with 78*. A beta is in the making at the moment and a link is provided to get to the location of the xpi file which you could download and install to test it and perhaps offer some feedback to the author. https://addons.thunderbird.net/en-US/thunderbird/addon/columnswizard/

Thanks Toad, I found the module Sender Domain.

It's a replacement solution.

But it's could be a good feature that Thunderbird can include each knowed header's informations as columns...