Version:            (using KDE 4.3.4)
OS:                Linux
Installed from:    openSUSE RPMs

I use Kmail version 1.12.4 with KDE 4.3.4 on an Opensuse 11.2 system. 
  
Sometimes I am forced to write an HTML email - even if I do not like it. 

The present HTML composer of Kmail is not sufficient to generate or handle complex HTML. It lacks a lot of features. Therefore, I thought that using an external editor would help and/or that I somehow could import my own HTML code into mails which I want to send via Kmail. 

However, the HTML-code written in any external editor is automatically transformed and rewritten. Unfortunately, on the poor level the present Kmail composer can handle.   

Every DIV e.g. is transformed into a P-tag - mostly with a substantial loss of features. 

Basically, this is the same frustrating thing one experiences with the HTML-abilities of other open source programs which include a limited HTML editing today - e.g. by some Wordpress releases. 

In the good old days an author could write HTML-Code and it was respected. Now, after implementing (modified) parts of Tiny MCE or other HTML-composers into the software the HTML-code the user generates is changed (reduced) to a kind of minimum code the program's HTML editor can handle. 

One could discuss whether this is a bug in the case of Kmail. But I think, the philosophy in the present version is wrong already. No way is offered to generate HTML mail with the code the author wants to use !  

In my opinion, when I customize Kmail to use an external editor I obviously want to do my own things. And there should definitely be a way to import the HTML-code I wish into the HTML part of a mail.

For comparison I checked what Thunderbird offers. They have an option to import HTML into a new mail. This happens via a separate editor (editor) window - the code written there (or copied into it) is included in the HTML body of the (HTML-) mail as it is - i.e. unchanged. 

So, my suggestion is to 
* either accept HTML code from external editors and leave it untouched 
* or to offer a feature similar to Thunderbird's one, which gives the mail author a chance to import his own unchanged HTML code. 

On should find a compromise where you offer unexperienced users a simple integrated HTML composer within Kmail and people who know how to use HTML a way to import unmodified HTML code.