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Short guides on the parts of business email nobody explains: DNS records, spam placement, and what your options actually cost. No fluff, no whitepapers, just what you'd learn the hard way.
The three ways to run email on several domains, what each provider allows per domain and per address, the DNS every domain needs, and a sourced cost table.
/learn/email-hosting-for-multiple-domains
Choosing a provider→Workspace prices per user, not per domain: up to 600 domains per account and 30 aliases per user. Secondary vs alias domains, and what a team really pays.
/learn/google-workspace-multiple-domains
Choosing a provider→Gmail's aliases are all @gmail.com, and Send mail as for your own domains ends in January 2027. What Gmail, Google Workspace and a multi-domain host each do, and what they cost.
/learn/gmail-aliases-vs-multi-domain-email
Explainer→A mailbox is a person, an alias is another address into it, forwarding sends a copy elsewhere. What each is for, what providers include, and why there's no catch-all.
/learn/email-alias-vs-mailbox-vs-forwarding
Explainer→Same domain, different servers: web hosting follows the A record, email follows MX. Why you never need web hosting for email, and how to move mail off a web host.
/learn/email-hosting-vs-web-hosting
How-to→Changing from acmecorp.com to acme.com: build the new domain first, copy old mail over IMAP, switch MX, and keep the old domain receiving for weeks.
/learn/how-to-move-email-to-a-new-domain
How-to→In January 2027 Gmail stops sending as, and fetching from, accounts that aren't Google's. What keeps working, four ways to keep a custom-domain address, and their costs.
/learn/gmail-send-as-pop-ending
Authentication→What each record actually does, how the three chain together into real spoofing protection, and how to set all of them up on your domain in under an hour.
/learn/spf-dkim-dmarc-explained
Deliverability→The ten causes behind spam placement, from DNS to reputation to engagement, each with a concrete fix, ordered by how often they're the culprit.
/learn/why-emails-land-in-spam
Choosing a provider→What Workspace is great at, where it quietly costs you, and how the real alternatives (Microsoft 365, Zoho, Proton, fastmail, self-hosting) compare on price and hassle.
/learn/google-workspace-alternatives
Authentication→p=none, quarantine, reject — what each policy does to failing mail, how rua reports reveal who sends as you, and a safe rollout to enforcement.
/learn/dmarc-explained
Original data→The same 5,000 domains, six weeks on: what changed, which providers receive their mail, how many DMARC records use the new tags, and how many BIMI logos Gmail can show. CSV included.
/learn/email-auth-census-2026-10
Original data→We ran dig across the Tranco top 5,000 — SPF 75.1%, DMARC 68.5% (51.8% at p=reject), MTA-STS 2.8%. Full methodology, tables, and findings.
/learn/email-auth-census-2026
Reference→SPF, DKIM, MX, DMARC, MTA-STS, TLS-RPT, BIMI — what each record does, what receivers check, and how the whole chain fits together.
/learn/email-dns-records-guide
Deliverability→The fundamentals that decide whether cold email lands — authentication, warm domains, volume discipline, list quality — and the myths to ignore.
/learn/cold-email-deliverability
Deliverability→Why new and dormant senders start in spam, what warmup actually consists of, and a safe week-by-week ramp with real engagement.
/learn/email-warmup-explained
Infrastructure→When a dedicated IP is worth operating and when a well-managed shared pool is the better engineering choice — no FUD, just trade-offs.
/learn/dedicated-vs-shared-ip
Email security→How the DNS record and HTTPS policy file force TLS for inbound mail, why it stops downgrade attacks, and how to deploy it with TLS-RPT.
/learn/what-is-mta-sts
Deliverability→Identify which list matters, fix the actual cause behind the listing, request delisting the right way, and monitor so it never recurs.
/learn/blacklist-removal
AI agents→The options, from a seat at your email provider to an agent inbox next to your team, and the seven decisions that keep an agent contained.
/learn/ai-agent-email-address
AI agents→List prices for a seat, a shared mailbox, an email API for agents and a do-it-yourself build, and the costs that aren't on any price list.
/learn/ai-agent-inbox-cost
AI agents→How hidden instructions in an email hijack agents, the incidents so far, and the layered defenses that limit what a tricked agent can do.
/learn/email-prompt-injection
AI agents→Which emails a person should approve, what the approval should show, and how to keep an agent from going around it.
/learn/human-in-the-loop-email
AI agents→What Article 50 of the EU AI Act asks of agents that email people, in force since 2 August 2026, and what a good disclosure line says.
/learn/eu-ai-act-email-disclosure
AI agents→Your main domain, a subdomain, a separate domain or a shared one: what each does for trust, authentication and your team's reputation.
/learn/ai-agent-sending-domain
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