Free Resources
30 reference documents for email infrastructure operators.
Checklists, configuration references, runbooks, and templates. No registration required, no email gate, no PDF wall — these are HTML pages designed to print cleanly to PDF if you want a paper copy. Open them, copy what you need, get back to fixing whatever broke.
Why these are free
A reference document gated behind a form is a worse reference document. The operator trying to debug an SPF error at 11pm does not need a marketing funnel — they need the answer. The IP-warming checklist is most useful when it is two clicks away from a search result, not three forms and a confirmation email later. So the resources here are open, by deliberate choice. They are also intentionally less polished than commercial deliverability whitepapers; the goal is operational utility, not lead generation.
The reading order
Operators arriving at this hub usually have one of three needs. Either something is broken right now (the runbook in Deliverability Operations is the right entry point), or you are setting up infrastructure for the first time (start with Authentication, then IP Reputation, then MTA Administration), or you are evaluating an architectural decision (the ROI worksheet in Compliance & Business and the migration checklist in Cold Email & Migration are the relevant tools).
If you are entirely new and unsure where to start, the order is: Email Authentication Setup Checklist → IP Warming Checklist → Deliverability Incident Response Runbook → Weekly Monitoring Template. Those four documents cover the operational stack from foundations to ongoing practice.
Email Authentication5 resources
The five authentication resources cover the full SPF, DKIM, DMARC stack from initial configuration through enforcement and ongoing maintenance. Since February 2024 (Google + Yahoo) and May 2025 (Microsoft), these are no longer optional for any domain sending more than 5,000 messages per day to those mailbox providers — proper authentication is required, and improper configuration is the most common reason senders see deliverability problems they cannot diagnose. The DMARC setup guide walks through the staged rollout (p=none → p=quarantine → p=reject) that actually works in production; the DMARC reporting guide is the companion piece for reading the XML aggregate reports without getting lost.
Email Authentication Setup Checklist
SPF, DKIM, DMARC, BIMI, and PTR setup verification with example records and commands
Open resourceDMARC Setup and Enforcement Guide
Staged rollout from p=none through p=quarantine to p=reject, with readiness checks at each step
Open resourceDMARC Report Reading Guide
XML aggregate report structure, key fields, and how to interpret each failure mode
Open resourceDKIM Key Rotation Guide
Zero-downtime DKIM rotation: generate, publish, configure, verify, decommission old keys
Open resourceSPF Record Troubleshooting Guide
Debugging the 10-lookup limit, syntax errors, and why your SPF record fails authentication
Open resourceIP Reputation Management7 resources
Seven resources covering the operational practice of building, monitoring, and recovering IP reputation. The IP warming checklist is the most-used resource in this hub — partly because warming is where most senders first realise their mental model is wrong (you do not just 'send slowly,' you send to your most engaged segment first while measuring complaint rate per ISP). The pool architecture guide answers the question that comes next: when does one IP become several? The Postmaster Tools guides for Gmail, Microsoft SNDS, and the consolidated ISP postmaster guide cover the data sources every reputation diagnostic depends on.
IP Warming Checklist
30-item checklist for new IP warming: pre-send preparation, weekly monitoring targets, post-warming verification
Open resourceIP Pool Architecture Design Guide
Single-IP, multi-IP, and stream-separated pool designs by volume tier — and when each makes sense
Open resourceIP Blacklist Removal Guide
Spamhaus, Barracuda, SORBS — the delisting process per blocklist with evidence templates
Open resourceGoogle Postmaster Tools Guide
How to register, verify, and read each Postmaster Tools view (domain reputation, spam rate, IP rep)
Open resourceMicrosoft SNDS Monitoring Guide
JMRP and SNDS registration, daily monitoring of Green/Yellow/Red status, complaint rate trends
Open resourceISP Postmaster Tools Setup Guide
Aggregate setup guide for Google, Microsoft, Yahoo postmaster tools — what each provides
Open resourceFBL Setup and Processing Guide
Yahoo FBL, Microsoft JMRP, suppression integration — the complete data pipeline
Open resourceMTA & Server Administration6 resources
Six configuration references for operators running their own infrastructure rather than consuming a managed service. The PowerMTA domain block reference is the dense one — every directive you can set in a domain block, with the calibrated values for each major mailbox provider that actually work in production. The MailWizz setup checklist and cron job reference cover the most common self-hosted email marketing application; if you are running MailWizz, these are the two resources you reach for during installation and on the day a cron job mysteriously stops firing. The server hardening checklist is the OS-level baseline — fail2ban, SSH key auth, firewall rules — that every production email server should pass before going live.
PowerMTA Domain Block Configuration Reference
The complete domain-block directive reference with calibrated values for Gmail, Yahoo, Microsoft
Open resourcePowerMTA Accounting Log Field Reference
Every field in the PowerMTA acct.log, what it means, and which fields matter for each type of analysis
Open resourcePowerMTA vs. Alternative MTA Comparison
Side-by-side comparison: PowerMTA, KumoMTA, Postfix, Halon, MailerQ — features, cost, operational fit
Open resourceMailWizz Cron Job Configuration Reference
The full set of MailWizz cron jobs, recommended frequencies, and why each one matters
Open resourceMailWizz Installation and Setup Checklist
Server prerequisites, database, cron, SMTP delivery server, integration testing
Open resourceEmail Server Security Hardening Checklist
OS-level hardening, SSH key auth, fail2ban, firewall rules — the security baseline for production
Open resourceDeliverability Operations7 resources
Seven resources for the operational practice of running a deliverability-aware email programme. The incident response runbook is the document you want already written before the 2am pager fires — three incident types (blacklist listing, Gmail spam classification spike, ISP-level block) with ordered response procedures and the data sources each step requires. The infrastructure audit template is the once-a-quarter health check; the weekly monitoring template is the Monday morning routine that catches problems while they are still small. The bounce code reference, glossary card, and list hygiene practices document round out the desk-reference layer that operators consult during the day.
Deliverability Incident Response Runbook
Step-by-step procedures for blacklist listing, spam classification spike, and ISP-level block
Open resourceEmail Infrastructure Audit Template
Full audit framework: authentication, IP reputation, MTA config, list quality. Scoring sheet included
Open resourceEmail Deliverability Quick Reference
Glossary card: every term, acronym, and protocol an operator encounters, defined in one to two sentences
Open resourceEmail List Hygiene Best Practices
Sunset policies, spam trap detection, re-engagement criteria, and the operational cadence for keeping a list clean
Open resourceWeekly Monitoring Template
The 12 metrics to check every Monday morning, with target ranges and escalation thresholds
Open resourceRe-Engagement Campaign Template and Strategy
The only legitimate exception to "once suppressed, never re-mailed" — how to run it without damaging reputation
Open resourceSMTP Bounce Code Reference
Every 4xx and 5xx bounce code, what it means, and the correct suppression action for each
Open resourceCold Email & Migration3 resources
Three resources for the structural decisions that come before warming and ongoing operations. The cold email infrastructure checklist covers the three-tier separation pattern (cold / marketing / transactional on isolated infrastructure with separate domains and IPs) that keeps cold email's higher complaint risk from contaminating the rest of the programme. The ESP migration checklist is the document that prevents the most common migration failure — losing the suppression list during the cutover, which produces a complaint rate spike on day one and damages the new IP's reputation before warming has begun. The transactional vs marketing separation guide explains why these two streams must never share infrastructure.
Cold Email Infrastructure Setup Checklist
Three-tier domain rotation, isolated sending IPs, warming cadence — the full cold email setup
Open resourceESP Migration Checklist
Pre-cutover, cutover day, post-cutover warming. Includes the suppression-list verification step most operators miss
Open resourceTransactional vs Marketing Email Separation Guide
Why transactional and marketing must run on separate IPs and domains — and how to architect the separation
Open resourceCompliance & Business2 resources
Two resources covering the layer above operational infrastructure — what regulators expect and what the financial trade-off looks like. The GDPR compliance checklist is calibrated to operational practice rather than legal theory: lawful basis under Article 6, consent collection mechanics, data retention defaults, the operational reality of handling Data Subject Access Requests at scale. The ROI worksheet is the cost-comparison framework that quantifies the dedicated-versus-ESP decision at your specific volume; below 50,000 emails per month, the math usually points to a managed ESP, and the worksheet says so explicitly rather than burying the answer.
GDPR Email Marketing Compliance Checklist
Article 6 lawful basis, consent collection, data retention, DSAR handling — the operational compliance reality
Open resourceEmail Infrastructure ROI Worksheet
Cost comparison framework: ESP per-recipient pricing vs dedicated infrastructure at your specific volume
Open resourceFrequently asked questions
Why are these resources free, with no email gate?
Are these PDFs?
How current are these documents?
Can I use these in my own documentation or training?
Which resource should I read first if I'm new to email infrastructure?
When the reference document isn't enough
The resources cover what's true in general. The right answer for your specific programme depends on volume, list quality, current deliverability state, and operational capacity. We run infrastructure assessments that map the general patterns to your situation — without a sales pitch built into the diagnosis.
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