Create 0008-email.md

[jamiehynds]

• Have you signed the contributor license agreement?
• Have you followed the contributor guidelines?
• For proposing substantial changes or additions to the schema, have you reviewed the RFC process?
• If submitting code/script changes, have you verified all tests pass locally using make test?
• If submitting schema/fields updates, have you generated new artifacts by running make and committed those changes?
• Is your pull request against master? Unless there is a good reason otherwise, we prefer pull requests against master and will backport as needed.
• Have you added an entry to the CHANGELOG.next.md?