S/MIME stopped working

[isdtor]

> >TBH this looks more like a gpg than a mutt problem, and I haven't 
> >figured out how to debug this. Same error for encrypting.
> 
> Yes, it sounds like something changed with either the GPGME version, or 
> perhaps a configuration file.  I can't offer much advice except to check 
> those things. :(

PEBKAC.

Files under ~/.gnupg deleted that shouldn't have been. Luckily I had a backup somewhere. Will know better next time.