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PowerMTA Experts

Guides

The whole library, in one place.

Each of these is written to be read on its own and kept current as the rules change. They are the reasoning behind our work — useful whether or not you ever hire us — with external sources attributed on the page.

01

Authentication & compliance

Getting authenticated, aligned and compliant with the rules that now decide whether bulk mail is accepted at all.

Email authentication: SPF, DKIM, DMARC How authentication and alignment actually work, through to DMARC enforcement, and the records that pass for the wrong reasons. Read the guide Bulk sender compliance The Gmail, Yahoo and Microsoft requirements compared side by side, with the spam thresholds and the exact rejection codes. Read the guide BIMI & VMC What it really takes to get a verified logo into the inbox, and which providers honour it. Read the guide

02

Infrastructure & migration

Choosing the engine that fits, and moving between engines without a deliverability cliff.

Choosing an MTA PowerMTA, KumoMTA, Halon, MailerQ — what each is for, and the honest trade-offs between them. Read the guide PowerMTA → KumoMTA migration How a migration preserves IP reputation, authentication and in-flight mail, cut over one pool at a time. Read the guide

03

Diagnosis & recovery

Finding out where you actually stand, and getting back to the inbox when something breaks.

The deliverability audit What an infrastructure-level audit checks — and where the typical audit stops short. Read the guide Blacklist delisting & recovery Which listing actually affects delivery, how each one clears, and how to stay off it. Read the guide

Want this applied to your own setup?

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