Sometimes a coworker sends an email to all company. When I receive
that kind of mail, sometimes I want to forward it to everybody in my
address book. The problem is, lots of other people in the company
already got that mail, so this will not be nice thing to do...

When forwarding an incoming mail, the mail client should check the
recipients other than me, and not forward to them at all... Is this
functionality already there in Thunderbird? Or can it be achieved by
some addon or st.?