A quick search of the info found no reference to RFC2015 or PGP/MIME.
(I'm not an expert in mailcrypt, pgp, or mime).
There is a mailcrypt mailing list. You might try there.
>>>> "Hrvoje" == Hrvoje Niksic
<hniksic(a)srce.hr> writes:
Hrvoje> nbecker(a)fred.net writes:
> I grabbed the new mailcrypt-3.5.5, untar'd it, did configure
&&
> make. Then manually installed the lisp into xemacs-packages.
> Worked fine. Sent myself encrypted mail, and it decrypted correctly
> (with gpg).
Hrvoje> Does it grok PGP/MIME (rfc2015)?