Wow! Full access to Thunderbird and my computer! Why asking for the maximum permissions? Nostalgy used to be my favourite add-on but I will not give it full permissions, sorry. I'll have to find something else or fork it. Too bad.
Thanks for your reply. I discovered that all extensions apparently ask for all permissions while, once installed, they are presented as "no permissions". Another weird aspect of Thunderbird. I installed your version, tested it and it is perfect. Thanks a lot for the port, opto. I'll donate because Nostalgy is absolutely essential.
There is no change in permissions as compared to before. Addons always had these permissions.
Same for other open source software. Libreoffice, for example, can create/write/delete (settings) files. It has 'full' access to your computer. I am pretty sure they could erase your harddisk (delete all your files) if they truely wanted.
Mozilla is trying to scare people away from the old addon type using strong words. But the new addon type can still hardly do anything near Nostalgy capabilities, we still need the old addon style.
To return some trust, the old addons are reviewed by real persons, not automatic.
I hope that info helps.