Optimize Proxmox Mail Gateway

I have a brand-new Proxmox Mail Gateway standing in front of my self-hosted Postfix server on Linux, and I want it locked down and tuned so far less spam ever reaches the inbox. I’m looking for someone who already knows PMG inside out—its GUI and CLI—plus the usual mail-flow companions such as SpamAssassin, ClamAV, RBLs, DKIM, SPF and DMARC. The job in a nutshell • Apply current best-practice hardening to Proxmox Mail Gateway: TLS policies, relay restrictions, rate-limiting, automatic updates and secure quarantine access. • Build an effective, low-false-positive spam-filtering ruleset: fine-tune SpamAssassin scores, integrate multiple real-time block lists and employ greylisting where it helps. • Enable and test antivirus scanning with ClamAV and any recommended signature feeds. • Make sure DKIM signing/verification, SPF and DMARC checks are enforced end-to-end so Postfix sees clean headers. • Provide short documentation outlining what you changed and where to tweak thresholds in future. Acceptance criteria 1. Proxmox Mail Gateway passes an external security scan with no critical findings. 2. MXToolbox reports DKIM, SPF and DMARC alignment as “Pass.” 3. Test messages from common spam test suites are stopped or quarantined, while legitimate mail from Gmail/Outlook arrives untouched. 4. A concise change log and a one-page “next steps” guide are delivered. You will have SSH and GUI access to both the gateway and the Postfix box; I’ll handle DNS changes and firewall openings as requested.