viewing messages on demand in a better page

[Thomas Glanzmann <sithglan@xxxxxxxxxxxxxxxxxxxx>]

Hello,
I want the following behaviour:

I am looking at a message and decide that it would be better to read it
in vim. So I press a key and vim popsup. The message should be read-only
of course.

Of course could I hit e and 'edit' the message. Howeve I am looking for
a read-only approach. Anyone has this already done?

        Thomas