Openings
Signing in for the first time, and binding the domains you already own.
The reader begins here
Three books,
bound together.
The Manual explains how to run Folio after signup. Openings covers sign-in, domains, and identities; Correspondence covers composing, replies, drafts, and threads; Housekeeping covers billing, deliverability, security, and troubleshooting. Start with the first chapter, then return when a DNS, sending, or billing question comes up.
This manual is the longer version of the prospectus — written for the evening you've signed up, your first domain is pending on the screen, and you want to know whether the fourth TXT record really does matter. The books are independent; most readers start at the first chapter of Openings and stop when things feel familiar.
Updated 11 May 2026 (2026-05-11)
Connect an AI assistant
Let an assistant read, never write.
Claude, ChatGPT, Cursor and Claude Code can search and read your Folio mail and calendar. They can't send, delete or change anything, and never see Spam or attachment contents. Revoke any of them from Connected apps.
Server URL
https://api.folioinbox.com/mcpClaude signs in to Folio itself — no key to copy.
In Claude, open Settings, then Connectors, and choose Add custom connector.
Name it Folio and paste the server URL.
https://api.folioinbox.com/mcpClick Connect. Folio asks you to sign in, then shows what Claude can read.
Choose Allow. Folio appears in Claude's tools menu for new chats.
Common questions
Where do readers start?
What's the fastest way to get a domain sending?
- Open the wizard at /app/domains/new, paste exactly the DNS records it shows at your registrar, then verify from the domain detail page. The base records cover MX, SPF, DKIM, and DMARC; carrier records may also appear for Amazon SES identity and MAIL FROM alignment.
How do I add a second identity to my account?
- Bind a second domain via /app/domains/new. Each domain becomes its own sending identity with its own DKIM key, its own color stripe in the inbox list, and its own auto-selected reply From.
Where do I read about deliverability — DKIM, SPF, DMARC?
- Book III chapter 2 (/docs/deliverability) covers the three records in detail and explains how Folio provisions them per-domain. The /writing/spf-dkim-dmarc-for-solo-founders essay covers the same ground for first-time operators.
Where do I find pricing and billing details?
- Book III chapter 1 (/docs/billing) explains the per-tier domain caps, the annual vs. monthly cadence, and how to manage your Stripe portal. /pricing has the marketing summary.
§ Sources & further reading
Correspondence
The daily act of reading and replying — stripes, signatures, drafts.
Housekeeping
Subscription, deliverability, sign-in security — the dull necessary chapters.
Colophon
Set in Fraunces (headings), IBM Plex Sans (text) and IBM Plex Mono (DNS and code). Sienna on warm paper, or on night in dark mode.