[horde] IMP: Encoding problem in message view

[김 덕곤]

Hello.

When I opening a message(that is not encoded in UTF-8),
character is not shown in correct encoding.

But, when I reply or forward it, correct character is shown.
(And, the replied message is encoded in UTF-8)

When I open a message as popup(Show all parts, and click on a part),
character is also in a wrong encoding,
but if I change character encoding to Unicode in a Browser option,
correct character is shown.
This means server already converted form encoding to encoding,
but wrong Content-Type is sent.

A message's encoding is 'ks_c_5601-1987'
Web page's encoding is 'UTF-8'.

Any suggestions?

Versions.
Horde : 5.2.8
IMP : 6.2.11