v4.8

## BillionMail v4.8

#### Domain Blacklist Detection

Added blacklist monitoring for domains with support for manual detection and auto-scanning. System will alert if domain or IP is blacklisted. Manual scan available in domain list; alert settings (notify email, recipient) configurable in settings page.

#### Bug Fixes
- Email Marketing: enhance tag logic to support NOT condition in batch mail processing
- Fixed the automatic scanning error of the Suspend List
- Fix the issue where unsubscribing becomes ineffective after enabling whitelist access.