---
title: "Deliverability articles"
description: "How mail reaches the inbox: SPF, DKIM, DMARC, sender reputation and the DNS records that decide where your messages land."
url: "https://nextmail.sh/blog/tags/deliverability"
---

[Blog](https://nextmail.sh/blog.md)

# Deliverability

How mail reaches the inbox: SPF, DKIM, DMARC, sender reputation and the DNS records that decide where your messages land.

Oct 31, 2026 5 min read

## SPF, DKIM and DMARC explained: how inboxes trust mail

What SPF, DKIM and DMARC each check, why alignment decides whether DMARC passes, and a safe order for moving a domain from p=none to p=reject.

Benjamin Deliverability

Oct 31, 2026 10 min read

## What is BIMI? Inbox logos and how to get a certificate

BIMI is a DNS record that puts your logo beside mail that passes DMARC. How the record, the BIMI logo and VMC or CMC certificates work, inbox by inbox.

Arta Deliverability

Oct 31, 2026 9 min read

## What is DKIM? How DKIM signatures and records work

DKIM is a signature on every email that proves which domain vouches for it and that nothing changed on the way. How it works, tag by tag, and which keys to use.

Benjamin Deliverability

Oct 31, 2026 9 min read

## What is DMARC? Policy, reports and getting to p=reject

DMARC is a DNS record that checks SPF and DKIM against your visible From domain, tells inboxes what to do with mail that fails and reports who sends as you.

Arta Deliverability

Oct 31, 2026 10 min read

## What is SMTP? How it works, from ports to reply codes

SMTP is the protocol that carries email from your app to your provider and between mail servers. How it works, which port to use and what each reply means.

Benjamin Protocols

Oct 31, 2026 9 min read

## What is SPF? How SPF records work and where they break

SPF is the DNS record that lists the servers allowed to send mail for your domain. How receivers check it, what each part means and what quietly breaks it.

Arta Deliverability

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