3.0.0

Breaking Changes

• Drop monit support by @nevart in #54
• Drop X-Spam-Level header, which provides no useful information by @nevart in #56

Features

• Support ASN lookup by @nevart in #57
• Support custom rules by @nevart in #58

Fixes

• README: add missing packages by @nevart in #59

Full Changelog: 2.1.0...3.0.0