There is a feedback forum here https://connect.mozilla.org Personally I see no potential benefits from becoming aware of the sending email address, as reported in the from that can easily be fraudulent as it is not used in the delivery process, before opening the email. There is no security benefit as nothing actually happens when you open the email to read it, except perhaps to download remote images if you have that enabled. It certainly does not unleash malware, download malware or run a script on your system. I do disable the use of the Thunderbird address book to replace the users choice of display name in their email with that in the Thunderbird address book. However I do that more from the fact sometimes folk change their display name to flag a change of hats on the same email address.