Discovering Uninstalled Alternatives for /etc/alternatives

[Smylers]

Hi there. How do I find out which packages provide an alternative for a
particular entry in /etc/alternatives?

For example, I recently spotted that the mutt command uses the
alternatives mechanism. So I wanted to know which other packages provide
a mutt command -- maybe one of those would have something interesting in
that I'd prefer to the Mutt I'm currently using.

update-alternatives only lists alternatives that I already have
installed:

  $ update-alternatives --config mutt
  There is only one alternative in link group mutt: /usr/bin/mutt-org
  Nothing to configure.

What I want is a list of all packages that provide a particular
alternative, so that I can consider installing them.

(For the particular case of Mutt aptitude search mutt listed
mutt-patched, among other things. So that answers my immediate question.
But that doesn't work in general for finding all possible alternatives,
and may also list an overwhelming number of packages that aren't
alternatives.)

Thanks

Smylers
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