Help # Changelog A record of notable changes to the Mission Inbox API and documentation. Breaking changes are always listed first within a release. October 28, 2026 ## Transactional sunset announced deprecated Mission Inbox is sunsetting the Transactional product. We will contact existing customers directly about timing and next steps. October 25, 2026 ## Reply forwarding replaces Reply-To new A mailbox can forward its replies to another address. Replies go to the mailbox itself and land in its inbox as usual, so your sending tool sees them, and a copy is forwarded to that address, still showing the original sender. Reply-To values saved on mailboxes, which mail sent over SMTP kept carrying until now, were turned into forwarding addresses for you. Check **Forward replies to** on a mailbox to see where its replies go. improved `replyTo` on `POST /api/mailboxes`, `PATCH /api/mailboxes/:email` and `POST /api/mailboxes/bulk-create` sets the forwarding address again; an empty string or `null` on update stops forwarding. It can also be set in the app as **Forward replies to**. Create and update answer 400 for an address that is a Mission Inbox mailbox (including the mailbox itself, with or without a `+tag`) or for a mailbox whose name forwarding cannot handle; in a bulk create that mailbox fails in the task results. removed Mail sent over SMTP no longer carries a Reply-To header, including one your sending tool or email client sets. The header hurt deliverability. If your tool sets Reply-To to send replies to another address, set **Forward replies to** on the mailbox instead. October 21, 2026 ## DNS provider keys in the API new `/api/dns-credentials`: connect, list, update and remove DNS provider keys (Cloudflare, GoDaddy, Porkbun, Spaceship, Dynadot, Vercel) through the API. With a key connected, records are pushed automatically when a domain is added. improved `POST /api/domains/push-dns`, `/create` and `/bulk-create` now document the automatic DNS push, `hasDnsManager` and `emailDns`. fixed Task monitoring now points at `GET /api/tasks/:id/events`, and the SSE examples show the events the stream actually sends. October 19, 2026 ## DNS change webhooks new `domain.dns_change_required`: when a change on our side means DNS records you publish for a domain must change, we send one event per domain listing every record to create, update or delete, with old and new values. Available to Transactional and Cold Outreach through `/api/webhooks`; Cold Outreach can subscribe to `domain.*` events only. new `POST /api/webhooks/:id/test` sends a signed sample event to an endpoint and returns what it answered. Also available as Send test in Settings → Webhooks. improved Every webhook payload now carries `version` (currently `1`) and `test` (true only on a sample from the test endpoint). Redirects are not followed: a 3xx counts as a failed attempt. October 17, 2026 ## Mailbox Reply-To disabled deprecated `replyTo` on `POST /api/mailboxes`, `PATCH /api/mailboxes/:email` and `POST /api/mailboxes/bulk-create` is deprecated and ignored. Requests that send it still succeed, but nothing is saved. removed A mailbox's stored Reply-To is no longer added to outgoing mail, on `POST /api/email/send` or over SMTP. A `reply_to` you put on the request is still sent as is. Without one, no Reply-To header is added and replies go to `from`. Reply-To values saved before this change can still appear in mailbox responses and exports, but they are not used. October 16, 2026 ## Domain Redirects removed removed **Breaking:** the Domain Redirects API is gone. Every `/api/domains/:domainName/redirect` and `/api/domains/redirects/*` endpoint has been removed, along with `redirectUrl` on domain create and bulk create, the `redirection` filter on `GET /api/domains`, the `redirect` field on domain and DNS record responses, and `redirectionConfiguredDomains` on `GET /api/domains/statistic`. October 1, 2026 ## Marketplace leasing and sequencer connections new The Domain Marketplace is now documented for API use: browse with `GET /api/marketplace/domains`, check `GET /api/marketplace/eligibility`, lease with `POST /api/marketplace/checkout`, and follow setup on `GET /api/marketplace/leases`. Cold Outreach only. new The bulk-connect endpoints (`bulk-connect-instantly`, `-smartlead`, `-emailbison`) and their connect-all variants take an optional `credentialId` to choose which sequencer connection to push to. Without it, the first active connection for that provider is used. September 24, 2026 ## Mailbox warmup moves to Premium warm-up removed **Breaking:** the previous warmup integration is gone. `GET /api/warmup/mailboxes/:email` no longer returns `warmyMailbox` or `warmyMailboxDetails`; read `emailBisonWarmup` (sync state) and `emailBisonWarmupStats` (sent, replies, saved from spam, warmup score, bounces) instead. Enabling and disabling warmup is unchanged. new `PATCH /api/warmup/mailboxes/:email/daily-limit` sets how many warmup emails a mailbox sends per day, with an optional `dailyReplyLimit` (a number, or `"auto"`). September 18, 2026 ## SEP connection details per mailbox new `GET /api/mailboxes/:email/sep-connections` reports, per platform, when a mailbox was connected and the SMTP/IMAP endpoint a connect pushes. Pass `provider` to report one platform. fixed Reconnecting a mailbox now moves its SMTP/IMAP endpoint at the platform. Connecting to Instantly always rebuilds the account, so a reconnect is enough to repair one that points at the wrong host. September 10, 2026 ## Tracking is set per sending domain removed **Breaking:** `DELETE /api/transactional/tracking-domain` has been removed, with no per-domain replacement: a tracking hostname can be changed with `PATCH /api/domains/:domainName` but not removed, so links in mail already sent keep working. To stop tracking, set `open_tracking` and `click_tracking` to `false`. deprecated The account-level `GET`/`PUT /api/transactional/tracking-domain`, `/verify` and `/push-dns` routes still answer, but act on whichever domain holds the newest hostname and will be removed. Move to the per-domain routes below. new Open tracking, click tracking and the tracking hostname now belong to each sending domain: `GET /api/domains/:domainName/tracking`, `PATCH /api/domains/:domainName`, and `POST /api/domains/:domainName/tracking/verify` and `/tracking/push-dns`. `POST /api/domains/create` accepts the same fields, so a domain can be registered with tracking already set. improved A send resolves each flag separately: the request first, then the domain, then the account default in `/api/transactional/settings`. A domain left at `null` inherits, so existing integrations behave as before. A replaced hostname keeps serving links in mail already sent. September 9, 2026 ## Domain registration info for Transactional new Transactional domains carry a `registrationInfo` block — DNS provider, name servers, registrar, registration and expiry dates, and age in days. `POST /api/domains/:domainName/registration-info/refresh` re-collects it on demand. September 8, 2026 ## Your own tracking domain, and the Pro plan new Transactional open and click tracking can be served from your own hostname, such as track.yourdomain.com, with one CNAME record. The certificate is issued automatically. improved The paid Transactional plan is now called **Pro** (previously Scale). Nothing about it changed except the name. Sales plans are still Lite and Scale. September 7, 2026 ## Transactional email is live new Mission Inbox now has a second product: **Transactional**, for the mail your application sends because a user did something — password resets, receipts, notifications. It runs alongside Cold Outreach on the same API, with its own key. new Send over REST with `POST /api/email/send`, or point an existing mail library at the SMTP relay on `smtp.missioninbox.com` (port `2587` STARTTLS, `2465` TLS) using credentials from `/api/smtp-credentials`. new Sending identities approve individual From addresses — `/api/sending-identifiers`. A send names a `from` address and it is resolved to its identity server-side, so an unapproved sender cannot get through. Each identity reports `canSend`, true only once its domain is verified and not blacklisted. new Delivery webhooks push eight event types (`message.sent`, `delivered`, `bounced`, `complained`, `rejected`, `delayed`, `opened`, `clicked`) to your endpoint, signed with HMAC-SHA256 in an `x-mi-signature` header. A failed delivery is retried up to six times over about two hours — seven attempts in all — and can be replayed by hand afterwards. new A suppression list is maintained for you: hard bounces and complaints are added automatically, and every send is checked before it leaves. A suppressed send is refused before composition — it is not billed and does not count toward volume. new Delivery analytics report volume and outcomes per From address and per domain, plus outcomes over time — `/api/analytics/sending-identity-stats`, `/domain-stats` and `/sending-activity`. new Domain setup is two DKIM `CNAME` records and one DMARC `TXT` record. There is no SPF, MX or return-path record to maintain, because nothing here routes inbound mail and delivery is authenticated by DKIM. improved These docs are now split into one tree per product. Doc URLs carry a product segment (`/transactional/…`, `/sales/…`), and the sidebar, search and next/previous links follow the product you are reading. Existing links without a product segment still work. July 4, 2026 ## Health checks now powered by GlockApps improved Inbox placement testing (`/health-check`) now runs on GlockApps, producing a much richer report: a per-provider delivery breakdown, enterprise spam-filter engine scores (SpamAssassin, Barracuda, Microsoft EOP, Proofpoint, Google), IP reputation & blocklist checks, and full SPF/DKIM/DMARC/MTA-STS detail. new Results now report placement _rates_ — `inboxRate`, `spamRate`, `otherRate` (tabs) and `notDeliveredRate` (0–100%) — plus a `provider` field indicating the testing vendor. new A normalized `glockapps` object carries the full detail (rates, per-provider seeds, authentication, filter scores, IP reputation, blocklists, diagnostic flags). `glockappsResult` exposes the raw vendor payload for anything not surfaced there. removed The legacy 0–10 `score`, `btobScore` and `btocScore` fields, along with the top-level `spfResult`/`dkimResult`/`dmarcResult` and per-seed `results` fields, have been removed. Use `inboxRate` for the headline metric and read authentication from `glockapps.auth`. June 30, 2026 ## Webhooks documentation published new The Webhooks guide is now live. Webhooks have been running in production for over a month — battle-tested quietly behind the scenes — and the documentation is now officially available so you can build against them. new The guide covers the payload envelope, the available event types (`MessageSent`, `MessageBounced`, `MessageLinkClicked`, and `DomainDNSError`), and full example payloads for each. new Request signing is documented: every delivery includes HMAC signature headers (`X-Postal-Signature` and `X-Postal-Signature-256`) computed over the raw request body with your webhook secret, with a verification example. June 26, 2026 ## Vercel DNS integration new Automatic DNS management now supports Vercel, joining Cloudflare, GoDaddy, Spaceship, Porkbun, and Dynadot. new Connect a Vercel account via API token to let Mission Inbox push and clean SPF, DKIM, Return Path, MX, and DMARC records for Vercel-managed domains automatically. June 15, 2026 ## Return Path record reinstated for better deliverability improved The Return Path (RP) CNAME record is mandatory again. A custom return path aligns bounce handling with your sending domain, which meaningfully improves deliverability and reputation — so we have brought it back. Domains now require five mandatory DNS records: SPF, DKIM, MX, DMARC, and Return Path. improved `POST /api/domains/push-dns` and `DELETE /api/domains/:domainName/dns` operate on all five records again. improved `POST /api/domains/verify` response again includes the `return_path` key in `dnsChecks`, and all five records must pass before sending. improved `GET /api/domains/:domainName` and `GET /api/domains/by-id/:id` responses again include the `returnPathStatus` field. improved `POST /api/domains/create` response again includes the `rpHost` and `rpValue` fields. June 4, 2026 ## Connect all mailboxes to a SEP in one call new New bulk SEP endpoints connect every mailbox in your product to a platform in a single call — `POST /api/mailboxes/connect-all-instantly`, `/connect-all-smartlead`, and `/connect-all-emailbison`. new The mailbox list is resolved server-side from your product API key, so there is no client-side cap. Mailboxes already connected are treated as a no-op. May 27, 2026 ## Dynadot DNS integration new Automatic DNS management now supports Dynadot, joining Cloudflare, GoDaddy, Spaceship, and Porkbun. new Connect a Dynadot account via API key to let Mission Inbox push and clean SPF, DKIM, MX, and DMARC records for Dynadot-registered domains automatically. May 20, 2026 ## Higher pagination limit for domain listings improved `GET /api/domains` and `GET /api/domains/export` now return up to 500 items per page — the `limit` maximum was raised from 100 to 500, and the default page size is now 30. May 15, 2026 ## Built-in health check email templates new New `GET /api/health-check/templates` endpoint returns the built-in B2B email templates — each with an `id`, `subject`, and `textContent` — so you can present a template picker (or pick one at random) before starting an inbox placement test. April 15, 2026 ## DNS simplification — Return Path record removed removed Return Path (RP) CNAME record has been removed from all domain DNS requirements. Domains now require exactly four records: SPF, DKIM, MX, and DMARC. improved `POST /api/domains/push-dns` and `DELETE /api/domains/:domainName/dns` now operate on four records instead of five. improved `POST /api/domains/verify` response no longer includes a `return_path` key in `dnsChecks`. improved `GET /api/domains/:domainName` and `GET /api/domains/by-id/:id` responses no longer include a `returnPathStatus` field. improved `POST /api/domains/create` response no longer includes `rpHost` or `rpValue` fields. April 4, 2026 ## SEP integrations & Domain Warmup new SEP Integrations API — connect Mission Inbox mailboxes to Instantly, SmartLead, and EmailBison via `GET /api/sep-integrations/:provider`. new Domain Warmup guide added covering the pro-tier automated domain warming workflow. new Domain Warmup API reference added — `POST /api/domain-warmup/start`, `/stop`, and `/status`. improved Domain Redirects API documented — configure per-domain click-tracking redirect URLs via `PATCH /api/domains/:domainName/redirect`. March 22, 2026 ## DNS provider expansion & documentation portal launch new Automatic DNS management now supports Porkbun and Spaceship in addition to Cloudflare and GoDaddy. new Documentation portal launched — full API reference, interactive Try It sandbox, and getting-started guides. new Bulk Operations guide added covering async `bulk-create`, `bulk-verify`, `bulk-push-dns`, and `bulk-delete` for domains and mailboxes. new Deliverability monitoring guide added with inbox placement tips, spam trap avoidance, and reputation signals. improved Analytics API expanded — per-domain and per-mailbox breakdowns available via `GET /api/analytics` query parameters. [PreviousSupport & Resources](https://doc.v4.missioninbox.com/sales/support.md)