SPF, DKIM, and DMARC with Postfix and Ubuntu 20.04

SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting and Conformance) are email authentication protocols that are becoming increasingly necessary to run a working email server. Even if you have valid MX, A, and PTR DNS records for your mail server, you may find that your emails are getting rejected […]

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OSSEC on Ubuntu 16

OSSEC is a HIDS (Host-based Intrusion Detection System) that can perform real-time logfile analysis, rootkit detection, file integrity checking, and notification. Resources: The home page, documentation, and current code. OSSEC works by assembling a “safe” profile of your system and then continuously checking files and processes for deviation from this profile. In particular, for a […]

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