It seems like this should work after JENKINS-3605 was fixed so I followed the documented reference format as clarified in JENKINS-2413 and JENKINS-5322 (i.e. ${ENV, var="VERSION"}

I can get access to the default variables, but not ones set by setenv plugin or by any build steps.

When this is fixed we should make sure that the recipients can be set as well as the email content.

There are a couple of related patches out there.
http://n4.nabble.com/Email-notification-recipients-as-a-variable-td1578247.html#a1578247
Access to node env variables: JENKINS-5465

I'm not sure if this should be opened against email-ext or setenv plugin.
http://wiki.jenkins-ci.org/display/JENKINS/Setenv+Plugin
http://wiki.jenkins-ci.org/display/JENKINS/Email-ext+plugin

There is not currently a setenv component in jira so I'm opening this against email-ext.

A recent discussion of this issue: http://n4.nabble.com/How-to-use-environment-variables-td1012822.html#a1012822