Comment 1 for bug 1013341

That is one issue that I hadn't figured out the best way to handle. Since it uses the gnus smime.el package which is external from VM, I don't think it should load the package automatically. But gnus is pretty standard with emacs...

Whats missing is probably a feature check when trying envoke that function and simply emitting a message referring the user to the manual (which should say one must add (require 'smime) in their .vm.preferences file). If the package is not loaded, ignoring the error would simply make the signature a button, which is okay along with the message.

The 'No CA configured' error is related to either of 'smime-CA-file' or 'smime-CA-directory' (from the smime.el package), the vm docs should point the user to this in the signature verification part of the section "Reading S/MIME messages". I can add this in.