BarracudaCentral.org - Technical Insight for Security Pros
Check Single URL (trustedsource.org)
Postmaster Tools – Google (gmail.com)
Smart Network Data Services (outlook.com)
- Register with Google to list domains then get verified. After the domain gets verified, you can monitor spam data, if any.
- Outlook.com will monitor the ip address that you request. And you can setup abuse reporting after successfully verifying the network ip.