- Roundcube
- QRコードフィッシング (Quishing)
- ワンクリック配信停止 (RFC 8058)
- Gmail/Yahoo一括送信者要件
- メール送信者認証(SPF/DKIM/DMARC/BIMI/ARC)
- DMARC (Domain-based Message Authentication, Reporting & Conformance)
- BIMI (Brand Indicators for Message Identification)
- ARC (Authenticated Received Chain)
- JMAP (JSON Meta Application Protocol)