patch
https://app.mailivery.io/api/v1/campaigns//enable-ramp-up
Turn on automatic volume ramp-up for a mailbox (campaign). Instead of sending the full email_per_day immediately, Mailivery starts low and increases daily volume over time according to the chosen rampup_speed — protecting reputation on a brand-new or recently warmed mailbox. Use slow for fresh domains, normal as a sensible default, or fast when you need to accelerate to the target volume.
Not sure what value to use? See Recommended Warm-Up Settings — match your intended cold-send volume (up to 50 emails/day), set response rate to your plan's maximum, and turn ramp-up on.