Mail Server Security Audit

What We Check

A Mail Server Security Audit examines the configuration and security posture of your mail infrastructure. We review the MTA, authentication mechanisms, DNS records, reputation and mail logs to identify misconfigurations, abuse indicators and deliverability risks.

Our audit covers:

• MTA configuration — Postfix, Exim or Sendmail settings, relay restrictions, recipient verification, connection limits, rate controls
• Open relay testing — verification that the server does not relay mail for unauthorized senders
• Authentication — SMTP AUTH configuration, SASL mechanisms, password policies, authenticated sender restrictions
• SPF records — correct syntax, included ranges, mechanism strictness, alignment with actual sending sources
• DKIM signing — key presence, selector configuration, signing policy, key length, rotation status
• DMARC policy — published record, policy enforcement level (none/quarantine/reject), reporting configuration, alignment mode
• Mail queue analysis — queue size, stuck messages, patterns indicating spam sending or abuse
• Outbound patterns — unusual send volumes, recipient patterns, content patterns suggesting compromise
• Blacklist status — server IP checked against major DNSBLs (Spamhaus, Barracuda, SORBS, Spamcop and others)
• IP reputation — sender reputation scores from major providers, feedback loops
• Dovecot/IMAP security — authentication settings, TLS enforcement, plaintext login restrictions, access controls
• TLS configuration — STARTTLS support and enforcement, certificate validity, cipher suites, TLS version
• Mail log review — authentication failures, delivery errors, suspicious patterns, brute force attempts, abuse indicators

Common Issues We Find

• Server compromised and sending spam through authenticated accounts with weak passwords
• SPF records too permissive or missing entirely
• DKIM not configured, misconfigured or using weak keys
• DMARC set to p=none with no plan to enforce
• Server IP listed on one or more blacklists without the operator’s knowledge
• Open relay through misconfigured trusted networks
• Dovecot allowing plaintext authentication without TLS
• Outbound spam originating from compromised web applications using the PHP mail function
• Mail queue growing with thousands of undelivered messages

What You Receive

• A detailed mail security report covering all areas listed above
• Current blacklist status across all major DNSBLs
• Risk-rated findings with severity levels
• Specific remediation steps for each issue
• SPF/DKIM/DMARC record recommendations where corrections are needed
• Follow-up consultation to discuss findings and delisting steps

Related Services

• Linux Server Audit — full server security audit including mail as part of the broader review
• Web Server Security Audit — web server configuration audit
• Emergency Server Review — immediate response for active spam sending, blacklisting or mail abuse incidents

Get Started

Review our pricing or contact us to schedule a mail server security audit.