Hello,
I received a mail which has been digitally signed via S/MIME. After
enabling S/MIME support for IMP, I got this error message:
Fatal error: Call to a member function getDescription() on a non-object
in /usr/share/horde3/lib/Horde/MIME/Contents.php on line 971
Using Evolution or Thunderbird, everything works fine.
Any ideas?
Regards, 
    Wolfgang