A note on mutt and lynx:
This took a while to figure out, but I think I have an answer. Later versions of mutt won't use lynx interactively if specified to do so in one's ~/.mailcap . To get it to use an interactive entry, you have to select your message with "v" (to view attachments, or a text/html message), then him "m" to force the interactive entry.
I've changed the system /etc/mailcap to do something akin to the "right thing". If any mutt users _don't_ want to use lynx, you can override that in your own ~/.mailcap .
Incidentally, before the system /etc/mailcap it was using xdg-open, which seems to have support for lynx/elinks/links2/w3m/etc, but I'll be danged if I could get that to work.