How many cold emails can you send per day without hitting spam?

By Kamran Mumtaz, founder of LeadPetrol. 6 min read.

Short answer: about 30 cold emails per inbox per day, with 2 to 3 inboxes per domain. If you need more volume, add domains and inboxes. Don't push each inbox harder.

That's the rule we run for every client. Here's the reasoning, how to ramp up, and the signs that you're sending too much.

Why the limit is per inbox, not per company

Gmail and Outlook judge each sending address and domain on its own history. A new inbox that suddenly sends 200 emails a day to strangers looks exactly like a spammer. The same 200 emails spread across seven warmed inboxes, each sending around 30, look like normal business activity.

So the question isn't "how many emails can my company send?" It's "how many can each inbox send and still look human?"

The numbers we use

Setting	What we use
Cold emails per inbox per day	Around 30
Inboxes per sending domain	2 to 3
Warmup before the first cold email	At least 2 to 3 weeks
Starting volume after warmup	10 to 15 per inbox per day, then ramp up
Maximum bounce rate	Under 2%

Need 900 emails a day? That's 30 inboxes across 10 to 15 domains. It sounds like a lot, but domains and inboxes are cheap compared with burning your sending reputation.

How to ramp up safely

1. Warm up first. Let warmup run for two to three weeks before any cold email. Keep it running afterwards.
2. Start low. Begin at 10 to 15 cold emails per inbox per day.
3. Increase weekly. Add a few emails a day each week while replies and placement stay healthy.
4. Stop at around 30. Past that point the extra volume rarely pays for the extra risk.

Signs you're sending too much

• Reply rate drops suddenly without any change to your copy or list. This is usually the first sign you're landing in spam.
• Bounce rate climbs above 2%. Stop and verify the list before sending more.
• Placement tests show spam or promotions for one or more inboxes.
• Warmup health scores fall in your sending platform.

If you see any of these, pause the affected inboxes, let warmup recover them, and fix the cause before sending again.

Volume isn't the lever. Relevance is.

The fastest way to more meetings is rarely more emails. In one of our client campaigns, 6,100 tightly targeted emails produced a 5.3% reply rate and 8 sales opportunities in three weeks. Sending the same volume to a loose list would have produced a fraction of that, and damaged the domains doing it.

Get the infrastructure right, keep each inbox at a human pace, and spend your effort on who you target and what you say.