Live Updated weekly · backwards-compatible by default

The changelog.

We ship every week. Reply detection, warmup, billing rails, the API and the agent surface: here's everything that landed, newest first.

47
Releases in 2026
~1.3/wk
Average cadence
2.4s
Reply detection P50
0
Breaking changes shipped
June 2026
Jun 19, 2026
engine 2.11
Shipped

Reply streaming v2: 2.4s inbound, end to end

We rebuilt inbound detection on push subscriptions instead of polling. Gmail API mailboxes ride Pub/Sub; Microsoft Graph mailboxes ride change-notification subscriptions. The moment a prospect replies, classification and the Claude draft are computed on the same hop.

  • P50 from inbound reply to a ready-to-send AI draft is now 2.4 seconds across Gmail and Graph senders.
  • SMTP/IMAP mailboxes fall back to a 30-second adaptive poll, down from 2 minutes.
  • The reply.received webhook now carries latency_ms and the draft inline, so you can auto-respond without a second round-trip.
Jun 11, 2026
warmup 3.4
ShippedImproved

Cross-customer warmup pool: tiered reputation

Every NuMail mailbox warms inside one shared, human-looking conversation network. We split that pool into reputation tiers so a brand-new domain never trades engagement with an aged, high-trust one, and inherits trust gradually as it earns it.

  • Three tiers (seedling, established, trusted) assigned from domain age, bounce rate, and reply health.
  • Mailboxes promote automatically; a wobble in placement demotes a tier and tightens volume instead of burning the domain.
  • Pool now spans 40k+ mailboxes, so warmup conversations look like real B2B threads, not a closed loop.
Jun 3, 2026
senders 1.9
Shipped

Mailbox ramp scheduling

New mailboxes now follow a daily send ramp instead of a flat cap. You set a target; NuMail walks volume up on a curve that mirrors how a real human inbox grows, and pauses the ramp on any deliverability signal.

  • Per-mailbox ramp editor: starting volume, daily increment, ceiling, and send window with timezone.
  • Ramp auto-pauses on a spam-placement or bounce spike and resumes once the mailbox recovers.
  • Exposed on the API at PUT /v1/mailboxes/:id via a ramp object.
May 2026
May 27, 2026
mcp v0.6
Beta

MCP server: public beta

NuMail now speaks the Model Context Protocol. Drop @numail/mcp into Claude Desktop, Cursor, or any agent runtime and your AI can run real outbound (create campaigns, triage the unibox, draft and approve replies) against the same API the dashboard uses.

  • 26 tools across campaigns, leads, mailboxes, unibox, and analytics, scoped to a workspace API key.
  • Read tools are open by default; write tools require an explicit allow_writes flag so an agent can't launch by accident.
  • Walkthrough and config on the MCP page →
May 19, 2026
ab 2.0
Shipped

Statistical A/B auto-promote

Subject and opener variants now resolve themselves. We run a sequential test on reply rate and promote a winner the moment it clears significance: no fixed sample size, no guessing when to call it.

  • Sequential testing means you stop as early as the data allows, without inflating false positives.
  • When a winner is declared, remaining sends shift to it automatically and the ab_winner.declared webhook fires.
  • Per-variant significance is readable any time at GET /v1/ab/variants/:id.
May 8, 2026
connect 1.5
Shipped

Stripe Connect white-label: general availability

Agency-tier white-label is out of preview. Bill your end-clients on your own Stripe, under your own brand, from sub-workspaces inside one parent dashboard. Money never touches us; we take 0% of it and step aside.

  • Custom-domain login at app.youragency.com with per-sub-workspace logo and color.
  • Stripe Checkout links auto-generated per client; daily payouts straight to your account.
  • Full story on the agencies page →
May 2, 2026
webhooks 1.4
ShippedImproved

Per-workspace HMAC webhooks

Webhooks went from one global endpoint to many, scoped per workspace and per event. Every delivery is signed with HMAC-SHA256 and a per-endpoint secret, so a sub-workspace's events can route to that client's own infrastructure.

  • Multiple endpoints per workspace, each subscribed to a subset of the 10 event types.
  • Signatures use a timestamped X-NuMail-Signature: t=…,v1=… header to block replay attacks.
  • Failed deliveries retry with exponential backoff for 24h and can be replayed by hand from the dashboard.
April 2026
Apr 9, 2026
senders 1.7
Shipped

Microsoft Graph senders

Outlook and Microsoft 365 mailboxes now connect over the Graph API, not SMTP. You get the same first-class send pipeline, warmup, and reply streaming we already gave Gmail API mailboxes, with proper OAuth and no app passwords.

  • Connect via Microsoft OAuth; tokens refresh silently and revocation surfaces as a mailbox.error event.
  • Graph change-notification subscriptions feed the same 2.4s reply stream as Gmail Pub/Sub.
  • Threading, In-Reply-To headers, and sent-folder placement match native Outlook behavior.
Apr 1, 2026
engine 2.6
Fixed

Reply classifier: thread-context fix

The classifier occasionally read an auto-reply that quoted the original email as a fresh positive reply. It now strips quoted history and signatures before scoring, so out-of-office and bounce-style autoresponders land in the right bucket.

  • Out-of-office and "wrong person" replies now classify correctly instead of pinging you as warm leads.
  • No action needed; the fix is server-side and re-scores nothing retroactively.
March 2026
Mar 17, 2026
unibox 2.2
ShippedImproved

Claude AI drafts: voice matching

Every draft is scored against the mailbox's own sent mail and shown with a voice-match number, so you can see at a glance which ones already sound like you.

  • Scored on the habits a reader notices first: sentence length, contractions, how a message opens and signs off.
  • A score of 0–1 on every draft in the inbox. Below three usable sent messages we say there isn't enough history yet, rather than showing a number we can't stand behind.
  • The score gates tone and nothing else — it can't tell you a draft is correct, and no reply is ever sent without you.

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