Base64 -- Gnus vs. Exchange

[Ian Soboroff]

Sorry if this is a FAQ, but I couldn't dig up a solution anywhere.
Pointers appreciated.

I have recently had the misfortune to get stuck behind an Exchange
server.  Exchange, as we all know, seems to enjoy re-encoding
perfectly reasonable and innocent text sections into base64 which Gnus
then refuses to decode.  ("Error while decoding: (error Invalid base64
data)".  (Believe me, I wrote some of the software that sends me mail,
and I _know_ it sends it as text/plain!  I tried adding a X-Get-Your-
Filthy-Mitts-Off-My-Encoding header, but that didn't help.)

My current solution is that I wrote a Perl script to decode base64,
and then I call it via the menus Article->Washing->Unix pipe, which
unfortunately has no keystroke.  The script is pretty dumb:

use MIME::Base64 qw/decode_base64/;
local($/) = undef;
print decode_base64(<STDIN>);

Can someone better at Gnus/Elisp help me to teach Gnus to just do this
right natively?  i.e. to decode base64 without extra mousing or
keystrokes, but when i view the message or MIME part?

Thanks,
Ian