Sendmail Server with Redis Cache

I need my existing Sendmail instance tuned so it can comfortably handle both outbound and inbound traffic while off-loading the heaviest look-ups to a Redis cache. The server is already up and running; what I’m missing is the right configuration to make message routing, queue management, and spam/recipient checks respond instantly instead of piling up under load.

Here’s what I expect from you:

• Review my current Sendmail configuration and identify the blocks that should query Redis instead of flat files or local databases.
• Deploy and configure Redis on the same host (or remote, if you suggest that’s wiser) with sensible persistence and security settings.
• Update Sendmail’s map definitions, queue settings, and any m4 macros so it calls Redis for alias, access, and TLS/session data.
• Stress-test the new setup, prove that mail flows correctly in both directions, and document the benchmarks.
• Supply me with a concise “how it works” write-up so I can maintain or port this stack later.

You’re free to bring along helper scripts, but the final product must be the running configuration files, any Redis init scripts you add, and the brief documentation. If everything survives a high-volume test run and passes standard deliverability checks (SPF, DKIM, DMARC already configured), the job’s done.