Dear Maintainer,

Mutt depends on moreutils package, but, it is not listed on dependencies, nor
suggestions.

I see that pee is necessary to open html messages.

With out moreutils package, when I try to open a html messages, it shows:

sh: 1: pee not found

After install moreutils package, it was ablle to open and read html messages.

This is most likely a system or user configuration issue.  Mutt uses
mailcap to decide how to deal with attachments.  See the section in the
manual <http://www.mutt.org/doc/manual/#mailcap> for more details about
how that works.

AFAIK, nothing internal to Mutt (or its default shipped configuration)
is trying to use "pee".  I would check the system mailcap /etc/mailcap
for the first text/html entry, and also your ~/.mailcap file (if
present) to see if that gives any hints about what is going on in your
case.