[imp] Subject line encoding problem

[Daniel A. Ramaley]

Hello. I've recently discovered an issue with Subject line encoding on 
our webmail server. It runs Horde 3.1.5 and Imp 4.1.5 (also Ingo 1.1.4 
and Turba 2.1.5, though i doubt the problem is with one of those). The 
problem is that for some encodings the Subject line is not encoded 
correctly.

For testing, i sent a message 3 times, each time selecting a different 
encoding. In both the Subject and the body i typed "日本語" ("Japanese 
language" in Japanese). I repeated the same test with kmail, a desktop 
e-mail client.

With Horde/Imp:

Encoding      Subject line
-----------   ----------------------------------
ISO-8859-1    ???
UTF-8         =?utf-8?b?5pel5pys6Kqe?=
ISO-2022-JP   =?UNKNOWN?Q?=1B$BF|K=5C8l=1B=28B?=

For both UTF-8 and ISO-2022-JP, the message body came through perfectly. 
For ISO-8859-1, the body just contained 3 question marks (but that 
seems understandable since 日本語 cannot be represented in ISO-8859-1). 
But the Subject line for ISO-2022-JP does not display correctly when 
the message is received. I'm not sure what encoding Imp put it in, and 
from its own use of "UNKNOWN" it looks like Imp wasn't so sure either.

With Kmail:

Encoding      Subject line
-----------   ----------------------------------
ISO-8859-1    =?iso-2022-jp?b?GyRCRnxLXDhsGyhC?=
UTF-8         =?utf-8?b?5pel5pys6Kqe?=
ISO-2022-JP   =?iso-2022-jp?b?GyRCRnxLXDhsGyhC?=

Kmail's handling of ISO-8859-1 was odd. I specifically asked for 
ISO-8859-1, but Kmail switched the subject encoding to ISO-2022-JP. It 
did encode the body as ISO-8859-1, turning it into question marks (as 
Imp did), but only after displaying a warning that it was going to do 
so.

Both Horde/Imp and Kmail handled UTF-8 perfectly.

But note the difference in ISO-2022-JP. Kmail encoded the Subject as 
well as the body in that encoding, as one would expect. But Horde/Imp 
mangled the Subject.

I've been through the settings looking for some knob to turn to fix 
this. Is there a setting i've overlooked? If so, what is it?

Also, why does Horde/Imp require the user to select the encoding in the 
first place? Desktop clients usually select the most appropriate 
encoding automatically. Kmail, for instance, usually uses either 
US-ASCII or ISO-8859-1. But if i type some Japanese characters into an 
e-mail, it automatically switches to ISO-2022-JP (the most common 
encoding for Japanese e-mail). I'm sending this message from Kmail as 
UTF-8.

------------------------------------------------------------------------
Dan Ramaley                            Dial Center 118, Drake University
Network Programmer/Analyst             2407 Carpenter Ave
+1 515 271-4540                        Des Moines IA 50311 USA