Email Security & Anti- Spam Technical Expert

**NO 3rd Parties or Sponsorship!

Duration: Ongoing as-needed basis

Location: Remote, prefer East coast

We are seeking a highly experienced Email Security and Anti-Spam Technical Expert for project-based consulting work. The immediate need is for an expert with deep knowledge of email delivery, URI/domain reputation and list systems, and Linux-based email infrastructure, particularly Postfix and Rspamd.

The consultant will initially provide technical guidance regarding the operation of URI/domain list (DBL) providers and how these services interact with anti-spam systems. Future work may involve analyzing specific email files and related mail-server logs/configuration, documenting technical findings, providing an affidavit, and potentially serving as an expert witness or participating in a deposition.

This is not primarily a mail-server administration role. The emphasis is on deep technical expertise, analysis, and the ability to clearly and defensibly explain technical findings.

Responsibilities:

• Provide expert-level consultation regarding email delivery, spam detection, domain reputation, and anti-spam technologies.
• Explain how URI/domain list and DBL providers operate and how their data is used by email security and anti-spam systems.
• Analyze how domains, URLs, sender information, originating mail servers, IP addresses, and other message characteristics are evaluated during spam detection.
• Review Postfix and Rspamd configurations to determine how a mail server is currently using list, reputation, and anti-spam services.
• Explain why a particular email was accepted, rejected, flagged, scored, or otherwise handled in a particular manner.
• Analyze raw email/EML files, including headers, routing information, authentication results, message content, URLs/domains, and other relevant characteristics.
• Correlate EML findings with Postfix/Rspamd logs and server configuration when necessary.
• Evaluate email origin and authenticity, including potential spoofing or manipulation.
• Clearly document the methodology used and the technical basis for conclusions.
• Potentially prepare and sign affidavits or declarations describing technical findings.
• Potentially participate in depositions or provide expert witness testimony regarding email systems, anti-spam technologies, and specific technical findings.

Requirements:

• Deep understanding of SMTP & internet email delivery architecture.
• Strong knowledge of URI/domain list and reputation systems (DBLs) and DNS-based blocklists.
• Experience with services such as Spamhaus or comparable email/domain reputation providers.
• Strong hands-on experience with Rspamd and its scoring, filtering, reputation, and list functionality.
• Experience with Postfix and Linux-based mail server environments.
• Strong understanding of email headers and raw EML/MIME message structure.
• Expertise in SPF, DKIM and DMARC.
• Understanding of email spoofing, sender authentication, IP/domain reputation, and message routing.
• Ability to analyze mail-server logs and configuration and correlate those findings with individual email messages.
• Strong Linux knowledge sufficient to understand and evaluate underlying mail-server environment.