Version:           1.9.50 (using Devel)
Installed from:    Compiled sources
OS:                Linux

I am using KMail from SVN trunk (today's build), but the same problem is also reproducible in KDE 3.5.9 (using Kubuntu Hardy packages).

I receive some e-mails from people that have German umlauts in their descriptive name. Everything is fine when I read such e-mails, but when I try to reply on such e-mail, I get the e-mail address split to two parts (in two To/Cc fields). For example:

- original e-mail address: Lüre, Miki <lure.miki@miki.com>

will get split into two To/Cc fields:
- first: Lüre
- second: Miki <lure.miki@miki.com>

Similarly, if I just click on e-mail address in preview window, I get new message (compose) window, but the e-mail address in To field is just Miki <lure.miki@miki.com>

When I have looked at message source, I can see that e-mail address is encoded strangely:
=?iso-8859-1?Q?L=FCre=2C_Miki?= <lure.miki@miki.com>

Note: I have just put some names in example to make in anonymous. If I developer would like get full example of such e-mail, please drop me an e-mail or ping Lure in #kontact channel (I am there from time to time).

It seems to me the main problem is that this e-mail description is not put in quotes ("") when presented to the user and then when reply is done, umlauts confuse KMail.