always open https gmail in firefox tab at mail address click

sudo apt-get install libpar-packer-perl

sudo pp -e 'exec qq{firefox --remote "openurl(https://mail.google.com/mail?view=cm&tf=0&to=@{[join q(,), map {s/^mailto://;$_} @ARGV]})"}' -o /usr/local/bin/gmail

set gmail as customized mail reader: