For emails, add missing features in Atomic testing.

[jborozco]

Use case

For injects using emails, we don't have all settings needed available in atomic testing. We previously had this features in openEX.

Missing features:

• Sender email address
• Reply to
• Messages header

(to be challenged):

• Dry run
• Comcheck

[Lhorus6]

Contrast this with the scenarios and simulations in which we have these possibilities.