Recommended Warm-Up Settings

If you don't know what to set, use this page. It covers the four warm-up settings that matter and gives you a safe starting point for each.

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You only need three things to get running

1. Add a mailbox → 2. Start warm-up → 3. Choose your settings (this page).

Everything else in this reference is optional.

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These endpoints use application/x-www-form-urlencoded

Send fields with -d in cURL, not -F. (The connect endpoints are different — those use multipart/form-data and -F.)

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Emails per day

Match the number of cold emails you actually intend to send from that mailbox — up to a maximum of 50 per day.

If you plan to send 20 cold emails a day from a mailbox, set warm-up to 20. If you plan to send 200, set 50 — you don't need to go higher. Warm-up volume is there to establish a sending pattern that looks like your real one, not to maximise raw volume.

Bash

curl -X PATCH https://app.mailivery.io/api/v1/campaigns/$CAMPAIGN_ID/update-email-per-day \
  -H "Authorization: Bearer $MAILIVERY_API_KEY" \
  -d "email_per_day=20"

Check your account pool first

Emails per day is drawn from an account-wide pool, not allocated per mailbox. Twenty mailboxes at 50/day each needs a plan covering 1,000/day. Check what you have before you provision:

Bash

curl -X GET https://app.mailivery.io/api/v1/account/limits \
  -H "Authorization: Bearer $MAILIVERY_API_KEY"

JSON

{
  "data": {
    "email_per_day": { "total": 310, "used": 26, "available": 284 },
    "email_accounts": 15,
    "email_accounts_need_attention": 5,
    "emails_sent_today": 0
  }
}

If you set a per-mailbox value that exceeds what's available, the request is capped by your account allowance.

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Response rate

Response rate is the percentage of your warm-up emails that receive a reply from the Mailivery network. Replies are a strong positive signal for sender reputation, so set it to the highest value your plan allows:

Plan	Recommended response rate
Starter	30%
Professional	55%
Business	55%

Bash

curl -X PATCH https://app.mailivery.io/api/v1/campaigns/$CAMPAIGN_ID/update-response-rate \
  -H "Authorization: Bearer $MAILIVERY_API_KEY" \
  -d "response_rate=55"

Higher reply rates consume more of your daily sending budget, so size your emails-per-day accordingly.

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Relayed sending caveat

If a mailbox's SMTP and IMAP email addresses do not match (for example, relayed sending), Mailivery treats the response rate as 0 regardless of what you set — replies can't be reliably routed back to the original sender.

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Ramp-up

Turn ramp-up on for any new mailbox. Rather than jumping straight to your target volume, ramp-up increases sending gradually — which is what a genuine new sender looks like.

Set it at connect time with with_rampup and rampup_speed, or enable it later. rampup_speed is required:

Bash

curl -X PATCH https://app.mailivery.io/api/v1/campaigns/$CAMPAIGN_ID/enable-ramp-up \
  -H "Authorization: Bearer $MAILIVERY_API_KEY" \
  -d "rampup_speed=normal"

rampup_speed	Use when
slow	Brand-new domain, or a domain with past deliverability problems
normal	Default. Most mailboxes.
fast	Established domain already sending real mail

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Sending schedule

Warm-up that sends at 3am every day doesn't look like a person. Pick the preset that matches how the mailbox owner actually works:

Bash

curl -X PATCH https://app.mailivery.io/api/v1/campaigns/$CAMPAIGN_ID/update-sending-schedule \
  -H "Authorization: Bearer $MAILIVERY_API_KEY" \
  -d "sending_schedule_preset=Weekdays - 8am to 6pm" \
  -d "timezone=America/Chicago"

Preset
Weekdays - 8am to 6pm	Standard business hours — the safe default
Weekdays - 7am to 7pm	Longer working day
Weekdays - 6am to 10pm	Widest weekday window
With Weekends - 8am to 6pm	Include Saturday and Sunday
With Weekends - 7am to 7pm
With Weekends - 6am to 10pm

On the connect endpoints the same setting is named sending_schedule_presets (plural). On this endpoint it is sending_schedule_preset (singular).

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By provider

The settings above apply to every provider. What differs is how you connect the mailbox in the first place:

Provider	Connect with	Notes
Google Workspace / Gmail	Connect a Google Mailbox (App Password)	Requires 2-Step Verification on the account and a 16-character app password.
Google Workspace / Gmail	Connect a Google Mailbox (OAuth)	Mailbox owner authorizes via Google consent — no app password. Invite-only; contact support to enable it for your account.
Microsoft 365 / Outlook	Connect a Microsoft Mailbox	Returns a Microsoft consent URL. The mailbox stays pending until the owner completes consent — call Start Warm-Up after that.
Custom SMTP	Connect Mailbox with SMTP	Needs full SMTP and IMAP host, port, username and password.
Any of the above	Get Secure Embed Form URL	Hosted form — your users authorize without you handling credentials.

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Next step

Once settings are in place, confirm the mailbox is healthy with Get Health Score, and watch Get Metrics over the first week.