Dear Mozilla Team, since years there is am anoying trivial issue with importing PGP-Keys in Thunderbird. If you got an mail with public-Key attached, it is impossible to import this public Key before you ave you own key-pair. There should be a hint or warning or friendly suggestion about this.
Imagine a PGP beginner following the general steps to establish a PGP-protected mail connection. Even being aware of all steps, it is not trivial to find the correct order, as this seems an arbitrarily limitation.
More user friendly would be to allow any key-import, but show an MessageBox like "You importet an public key. But it cannot be used before you create you own key-pair." optional asking "Do you want to create it now?".
I saw many students again and again suffering with this restriction.