Support reporting email addresses

This is a fairly similar problem: maintaining a list of email domain -> abuse contact (however there's no WHOIS data available so this would be purely manual).

Questions to answer:
- [ ] How to handle the two slightly different "types" of email domains and phishing domains?
- [ ] What information is needed in an email address report? You can just provide a URL for a phishing site but just providing an email address isn't going to work

Start with the two unanswered questions in the issue: distinguish email domains from phishing domains, and define the information required for an email address report. No files, tests, or entry points are identified, so first map the existing abuse-reporting flow before proposing scope. Done requires an agreed design for both report types and their required data.

Written by the indexing model from the issue text.