How many cold emails per day?

Why the per-mailbox limit matters

Mailbox providers watch sending behavior closely. A single inbox that suddenly fires out hundreds of cold emails looks exactly like a spammer, and it gets treated like one. Keeping each mailbox to a modest, human-looking daily amount is the difference between landing in the inbox and quietly disappearing into spam. It is a reputation game, and reputation is fragile.

How real volume scales

The trick is breadth, not intensity. You do not raise one mailbox to 500 a day, you run many mailboxes each sending a little. Twenty warmed mailboxes at 40 emails a day is 800 sends daily, with no single inbox ever looking aggressive. Spread across several dedicated sending domains, that scales cleanly while protecting your primary domain entirely.

What happens if you send too much

Overloading mailboxes triggers spam filtering, bounces, and in the worst case blocks that damage the sending domain's reputation for weeks. The recovery is slow and expensive, so the safe path is always to add capacity through more warmed mailboxes rather than chasing volume from a few. Warmup and low per-inbox rates are covered in depth in the deliverability guide.

The simple rule

Send like a person, scale like a system. Modest volume per mailbox, many warmed mailboxes, dedicated domains, and continuous monitoring. That is how outbound reaches real inboxes at scale, and it is exactly the infrastructure we run for every client.