git: 'send-email' is not a git command. See 'git --help'

I'm trying to send patches with the git send-email But I get the following error:

git: 'send-email' is not a git command. See 'git --help'.

How to make git send-email works ?

Related links:

http://www.kernel.org/pub/software/scm/git/docs/git-send-email.html

You need to install the git-email package for it to work.

On Ubuntu, the usual apt-get install git-email works fine. I can confirm the same for Fedora as well (yum install git-email).

cebewee mentions the rationale in the comments:

Linux distributions often like to split up packages to avoid dependencies needed only by optional functionality (like send-email).

Note that you have to configure it before starting.