Minor Description
Oozie's docs have:
=oozie.email.from.address= - The from address to be used for mailing all emails (oozie@localhost by default).
(From http://incubator.apache.org/oozie/docs/3.1.3/docs/DG_EmailActionExtension.html)
However, the code does not seem to use a default when loading the prop from the Oozie conf. Thus if someone does not specify it, it causes an NPE when it tries to from a fromAddress object later.
Same applies to:
oozie.email.smtp.host - The host where the email action may find the SMTP server (localhost by default).