[Users] Set display type in the message preview pane

[Adrian]

I've tried to find the answer in the documentation but I probably
haven't got the right names for things.

In the default (or at least a common) layout of Claws Mail, the account
and folder list is on a left hand bar.  To its right the list of mails
in the current folder is shown in a top panel, and in the panel below a
message preview is shown.

To the right of the message preview pane is a narrow vertical bar with
two or more icons: the top one with an @ sign is labelled Type:
message/rfc822, and underneath are icons for each mime Content-type in
the message.

Most of the time, the view I see is the one corresponding to the top
'@' icon, which displays all header lines.  Since I moved to DKIM
signing and verification, various signatures and related fields make
the header so big that I have to scroll down to see the message content.

I realise that with multipart MIME there may be a number of different
displays.  I'd choose: display the text/html part if present, otherwise
display text/plain.

You may advise me to use text/plain for security and privacy
reasons, and I may agree with you.  The main thing is, I don't want to
see fifty header lines in the message panel every time I go to a new
message.

Is there a GUI or clawsrc etc setting to do this?

Thanks, Adrian