How many cold emails per day per mailbox

Plan on about 50 cold emails a day per mailbox, at least 10 minutes apart, and less for a new mailbox. Those are AY Inbox's defaults: a 50 a day campaign limit, a 600 second gap, and warmup that starts at 10 a day and rises by 1 a day to 40. To send more, add healthy mailboxes instead of pushing a few harder.

A sending limit here means the most cold mail one mailbox sends in a day, and the shortest gap between two of its sends. AY Inbox is mailbox-first: a campaign's daily volume is the sum of its mailboxes' budgets, not one global number.

The defaults

Limits stack, and the smallest wins. A campaign's daily limit can lower a mailbox's volume but never lift it above the mailbox's own cap, and campaign budgets reset at midnight UTC. The minimum gap is a bound of its own: at 600 seconds a mailbox can send at most about 144 emails in 24 hours, so a cap above that does nothing without a shorter gap. See sending limits for every limit and how they combine.

A new mailbox

Start a fresh mailbox at around 10 to 20 cold emails a day and raise it only while it stays healthy: no bounce spike, no complaints, no spam placement in its warmup mail. 30 to 50 a day is the normal band for a warmed mailbox. Going above 50 should take positive reputation evidence and a deliberate review, not a guess.

AY Inbox enforces part of this for you. A mailbox that warmed with AY Inbox starts cold sending at 5 a day and rises by at most 5 per clean day, and only as fast as confirmed human replies from real recipients allow. A mailbox that never used warmup is not held to that ceiling. See easing out of warmup.

Why spacing matters

A mailbox that sends exactly 40 emails a day, starting at 09:00:00 and exactly 600 seconds apart, describes itself as a machine. Newly connected mailboxes therefore get a variable sending plan, a randomized workday in the mailbox's own timezone (or the workspace's, when the mailbox has none):

Inside a campaign's sending window, AY Inbox spreads the day's emails across the hours left, adds jitter, and never sends a missed step late at night to catch up. The hourly ceiling matters as much as the daily one: without it, a mailbox could empty its whole day before 11am.

Warmup and cold are separate budgets

Warmup mail and cold mail are counted apart. Warmup follows the same working days and hours but is not charged against the cold daily or hourly ceilings; it has its own ramp. Keep warmup running after a campaign starts, rather than stopping it once the mailbox looks ready; while a campaign is live, AY Inbox limits that mailbox's warmup to a few messages a day so campaign mail stays primary. See warmup and email warmup.

Scaling

Volume should come from more healthy mailboxes, never from forcing a few to send more:

1. Add mailboxes at the default cap. A campaign paces the day's capacity across its whole sending pool, so a second healthy mailbox roughly doubles how fast it works through its leads, while each mailbox stays inside its own cap, hourly ceiling and gap.
2. Spread across sending domains. Mailboxes on one domain share its authentication and are judged partly on its reputation, so with several domains a problem on one holds back only the mailboxes on it.
3. Read the plan before touching a cap. A campaign's Today's sending plan lists every limit that lowered today's sends: the campaign limit, the ramp, easing out of warmup, other campaigns on the same mailboxes, health bands, the mailbox's workday and the sending window. A short day is usually one of those, not the cap.

Before launch, the campaign estimate simulates the same rules day by day and labels what sets the pace, so you can see a finish date before anything sends.

Signs to slow down

Bounces and complaints matter more than throughput. Google asks senders to keep their user-reported spam rate below 0.10% and never reach 0.30%. AY Inbox acts on a mailbox before that point:

At 20% spam placement a mailbox is throttled: cold volume is halved and warmup runs at half volume with double spacing until it recovers. A quarantined mailbox has cold sending paused and leaves the shared paid warmup pool for 7 days. Complaints need 100 delivered emails in 30 days, and spam placement 20 verified warmup deliveries in 7 days, before those bands apply. Details and recovery are in deliverability; the provider guidance behind the numbers is in the deliverability handbook.

If bounces or complaints start rising, stop the campaign and find the cause (usually the list) before sending more.

What limits do not promise

No daily number guarantees inbox placement. Staying under these limits avoids the patterns that providers and spam filters penalize, but placement still depends on authentication, your domain's reputation, your list and what you write. A configured cap is a ceiling, not evidence that a mailbox is ready for that volume. To see where mail actually lands, run an inbox placement test.

Frequently asked questions

How many cold emails can I send per day from one mailbox?

Plan on about 50 a day from a warmed mailbox, at least 10 minutes apart, and 10 to 20 a day from a freshly connected one. AY Inbox's default cap is 50 a day per mailbox, and 20 a day for a new free Gmail or Outlook.com account.

How long should I wait between cold emails from the same mailbox?

AY Inbox's default minimum gap is 600 seconds (10 minutes) between two sends from one mailbox, and 900 seconds on a new free Gmail or Outlook.com account. With a variable sending plan on, each gap is drawn between 90 and 420 seconds and an hourly ceiling of 5 to 9 sends stops bursts.

Does warmup count against my cold email limit?

No. Warmup and cold outreach are separate budgets. Warmup has its own ramp, 10 a day rising by 1 a day to 40 by default, and does not count against the cold daily or hourly ceilings.

How do I send more cold email per day safely?

Add healthy mailboxes at the default cap instead of raising the cap on a few. A campaign paces its day across the whole sending pool, so a second healthy mailbox roughly doubles how fast it works through its leads.

What is the maximum daily limit in AY Inbox?

A mailbox or campaign cap can be set up to 5,000 a day, for high-capacity mailboxes, and the dashboard warns above 100. A configured cap is a ceiling, not a target or evidence that the volume is safe.