This blog guide outlines essential recommendations and configurations. Here’s the key practices for best security:

Email Authentication

• Require SMTP Authentication: Ensures only users who validate their identity with a username and password can send mail.
• Use the IP Shield: Associates domains with authorized IPs to prevent spoofing & provide an extra layer of authentication.

🛡️ Data Protection

• Enable SSL/TLS: Encrypts the connection between mail clients & servers, and between mail servers & gateways.
• Use RequireTLS & MTA-STS: Enforces secure delivery paths for emails.
• PGP Encryption: Encrypts email messages between users.

Prevent Hacking & Abuse

• Block Open Relays: Prevents unauthorized email relaying, which happens when an email is neither to nor from a local user/domain.
• Enable MDaemon AntiVirus: Scans all inbound & outbound email traffic for malware using the Ikarus & ClamAV antivirus engines.
• Enable SMTP & Dynamic Screening: Blocks suspicious connection patterns and brute-force login attempts.
• Enable Account Hijack Detection: Limits outbound mail bursts to prevent spam from hijacked accounts.
• Location, IP, and Host Screening: Blocks connections from untrusted or unauthorized sources.
• Use Trusted Hosts/IPs Wisely: Only add trusted sources to bypass certain security tests.
• Enforce HTTPS for Webmail: Secures webmail sessions.
• Enable Two-Factor Authentication: Adds an extra layer of login protection.

Prevent Hacking & Abuse

• Block Open Relays: Prevents unauthorized email relaying, which happens when an email is neither to nor from a local user/domain.
• Enable MDaemon AntiVirus: Scans all inbound & outbound email traffic for malware using the Ikarus & ClamAV antivirus engines.
• Enable SMTP & Dynamic Screening: Blocks suspicious connection patterns and brute-force login attempts.
• Enable Account Hijack Detection: Limits outbound mail bursts to prevent spam from hijacked accounts.
• Location, IP, and Host Screening: Blocks connections from untrusted or unauthorized sources.
• Use Trusted Hosts/IPs Wisely: Only add trusted sources to bypass certain security tests.
• Enforce HTTPS for Webmail: Secures webmail sessions.
• Enable Two-Factor Authentication: Adds an extra layer of login protection.

Spam Prevention

• Spam Filter & Spam Scoring: Utilizes SpamAssassin rules for identifying spam.
• Bayesian Learning: Trains the filter using user-submitted spam/non-spam messages.
• DNS Blocklists: Blocks known spam sources in real-time.
• Enable Automatic Spam Filter Updates: Keeps spam definitions current.
• Spambot Detection: Blocks mass spam senders using multiple IPs.
• Spamhaus DQS: A paid service that blocks up to 99% of threats.
• Outbreak Protection: Detects and stops threats using pattern analysis even before antivirus signatures are updated.

When combined, these features form a comprehensive security framework that helps protect MDaemon mail servers from a wide range of email-borne threats.