Flow Logic (valid from 1 December 2008)

1. If the system is down, for any reason, all incoming requests are rejected (blank or error pages are rejected requests).
2. Check service user IP against databases. If the IP test fails, the IP is stored to the local database and the request is rejected.
3. If neither IP and email are given, accept.
4. If only the email is given, return email literal format check result.
5. If an IP is given, it is checked against the local and remote IP databases. If the IP test fails, the IP is stored to the local database and the request is rejected.
6. If an email address is given, it is checked against the local database and eventually against a remote SMTP mailbox. If the email test fails, the email and IP are stored to the local database and the request is rejected.
7. Accept.