Benchmarks / Reply timing

How long should you wait before following up on a cold email?

Based on 850 million+ emails · Smartlead platform data

About 3 days. 64% of cold email replies arrive within an hour, 88.5% within 24 hours and 93.9% within 72 hours. Waiting longer than 3 days before the next email gains at most the last 6.1%.

How fast cold email replies arrive

Share of all replies that arrive within each time after the email is sent. Built from more than 850 million emails sent through Smartlead.

Time after sending	Replies already in	Replies still to come
1 hour	64.0%	36.0%
24 hours	88.5%	11.5%, about 1 in 9
72 hours	93.9%	6.1%, about 1 in 16

What the data shows

Replies come fast. Nearly two in three arrive within an hour of the email.

The first day holds most of the rest. Another 24.5% arrive between the first hour and the 24-hour mark.

Then the flow slows. Only 5.4% arrive between 24 and 72 hours, and 6.1% arrive later than that.

That makes 3 days a natural gap between emails. By then, 94 in 100 replies to an email have arrived.

How this compares with common advice

Most guides recommend waiting 2 to 5 business days before the first follow-up. The data backs that range. After 3 days, 93.9% of replies have arrived. After only 1 day, about 1 in 9 is still to come.

What this data can't tell you

It shows when replies arrive, not whether a longer gap changes how the next email performs. It doesn't say whether automatic replies, such as out-of-office messages, are included, and it counts hours after sending, not business days.

How to use these benchmarks

Set the first follow-up about 3 days after the first email. The follow-up timing guide covers the gaps for later steps.
Check replies in the first hour after a send, when 64% of them arrive. A unified inbox keeps replies from every mailbox in one place.
Send when people are working. Reply rates peak between 6am and 10am in the recipient's time zone.
Keep the sequence to 3 or 4 emails. The median sequence runs 3 emails.
Don't skip the follow-up because the first day was quiet. The second email earns 0.73%, 62% of the first email's reply rate.

Frequently asked questions

How long after sending an email can you follow up?

After about 3 days. 93.9% of cold email replies arrive within 72 hours, so by then most people who were going to reply to that email already have. Waiting longer gains at most the last 6.1%.

How long does it take to get a cold email reply?

Usually under an hour. 64% of replies arrive within 1 hour of the email, 88.5% within 24 hours and 93.9% within 72 hours.

Should you follow up after 24 hours?

You can, but about 1 in 9 replies to the last email is still to come at that point. 88.5% of replies arrive within 24 hours and 93.9% within 72 hours, so a 3-day gap catches most of the rest.

Methodology

More than 850 million emails sent through Smartlead, using combined, anonymous platform data only. Only senders with at least 500 emails sent in the period are included. Each reply is timed from when the email it answers was sent, and each share is a share of all replies received.