Inboxes and warmup

An inbox is a mailbox ManyPI sends through. Everything about your deliverability — the cap, the ramp, the pause guard, the health score — hangs off it. Manage them in Outreach → Sending, or read them over the API with GET /api/outreach/inboxes.

Connecting

Gmail / Google Workspace
Outlook / Microsoft 365
SMTP

Click Connect Gmail and authorise. OAuth means no app password to rotate, and revoking access in your Google account revokes it here too.

Send cold outreach from a secondary domain (getacme.com, acme-team.com), never the domain your invoices and support mail come from. Reputation damage on your primary domain is slow and painful to undo.

Before you send anything

Set up authentication on the sending domain. Without it you will land in spam regardless of how good ManyPI’s throttling is.

Record	Why
SPF	Authorises your provider to send for the domain.
DKIM	Cryptographically signs your mail.
DMARC	Tells receivers what to do with failures, and gets you reports.

Warmup

A brand-new domain sending 500 emails on day one gets filtered. Warmup ramps the daily cap gradually instead.

Setting	What it does
`warmup_enabled`	Turns the ramp on. Leave it on for any new domain or mailbox.
`warmup_start`	Emails allowed on day one.
`warmup_increment`	How much the cap grows each day.
`daily_limit`	The ceiling the ramp climbs toward.

The effective cap is always min(warmup cap for today, daily_limit). The scheduler uses that number — not the raw limit — so a campaign can never out-send its inbox’s warmup.

A reasonable ramp for a fresh Google Workspace mailbox: start at 10, increment by 5 per day, ceiling 150. Faster than that is where people get burned.

Health

Each inbox reports a rolling picture over the last 14 days:

sends today versus today’s cap
delivered, failed, opened, bounced
a 24-hour bounce rate
whether the bounce guard has paused it
a 0–100 health score

The score is delivery success, lightly penalised while un-warmed and heavily penalised for bounces. That weighting is deliberate: a failed send never reached anyone, while a bounce is a receiving server recording that you wrote to an address which does not exist — that is the thing that actually costs an inbox its reputation.

The bounce guard

If the 24-hour bounce rate crosses the safety threshold, ManyPI pauses the inbox automatically and records why. Sends stop; nothing is lost. Fix the cause — almost always an unvalidated list — and resume.

Email validation

Validating before you enroll is the fix for nearly every bounce problem.

Multiple inboxes

More inboxes means more daily volume without pushing any single mailbox past a safe cap. Campaigns can use them in several ways:

Strategy	Behaviour
`single`	Every send goes through one inbox.
`rotate`	Cycle through the campaign’s inboxes.
`round_robin`	Even distribution across inboxes.
`provider_match`	Match the sending inbox to the recipient’s provider (Google → Google, Microsoft → Microsoft).

Per-seat inbox limits: 2 on Starter, 5 on Pro, 15 on Business. The workspace cap is that number times your seat count.

Priority

When several campaigns share an inbox they compete for the same paced send slots. Each campaign has a priority from 1 to 10 — higher wins the next slot. Use it to make sure a hot campaign is not starved by a long-running background one.

Reading inbox health over the API

curl https://app.manypi.com/api/outreach/inboxes \
  -H "Authorization: Bearer mpi_your_api_key"

{
  "inboxes": [
    {
      "id": "…",
      "name": "Lena — outbound",
      "from_email": "lena@getacme.com",
      "sentToday": 34,
      "capToday": 60,
      "sent14d": 402,
      "failed14d": 3,
      "opened14d": 121,
      "bounced14d": 2,
      "bounceRate24h": 0.0,
      "sending_paused_at": null,
      "health": 92
    }
  ]
}

Use an inbox id as the smtp_config_id when creating a campaign or sending a one-off email.

Getting started

Lead generation

Email outreach

The agent

Scraping & APIs

Platform

Connecting

Before you send anything

Warmup

Health

The bounce guard

Email validation

Multiple inboxes

Priority

Reading inbox health over the API

​Connecting

​Before you send anything

​Warmup

​Health

​The bounce guard

Email validation

​Multiple inboxes

​Priority

​Reading inbox health over the API

Connecting

Before you send anything

Warmup

Health

The bounce guard

Multiple inboxes

Priority

Reading inbox health over the API