Timo Buhrmester writes:
> The convention is to prefix the quoted part with >. Sensible MUAs will
> identify that as a quote and make it stand out appropriately.

It's about as easy to do with gmail as with mutt. Click the "..." near the
bottom of the compose area (or hit down-arrow and then enter). Select each
part you don't want to quote, hit delete to delete that part. Repeat until
only the things you do want to quote are left. Type your response following
the quoted text to which you respond.

Gmail will generally send an RFC3676-compliant message if you respond to
one.

Arnt