When pasting copied text into a mail, it is formated, as it has been in its source. E.g. italic text copied out of an odt Document, or underlined and blue text copied out of the browser is inserted as italic or underlined and blue.
Is there a way to insert it unformatted as plain text ('italic', 'underlined and blue')?
In other applications this is often done by the shortcut 'ctrl+shift+v'.

In KMail composer, uncheck Options -> Formatting to disable pasting of formatted text.

Thanks for the quick reply. I forgot to mention the version I'm using: KMail 1.10.3 (KDE 4.1.3)
I found Options -> Formatting. Which stops HTML formatting as a whole. That's ok for me, because I never use HTML formatting in Mails.
I also found a button for resetting character formatting on the editor's toolbar. That's cumbersome, but ok as workaround in case one wants to use html formatting.
"Insert as unformatted text" would be a nice feature anyway.

If this issue is resolved, could you please add [SOLVED] to the beginning of the thread subject? Thanks in advance.

If you would like to see this feature in a future version of KMail, I would recommend filing a feature request for KMail on the KDE bug tracker.