The best time to send a cold email, and how many follow-ups to plan

This guide is for SDRs, founders and anyone sending cold email to businesses in the US who wants to know when to send and how often to follow up. It sets out what the published data shows and its limits, how to schedule across time zones, a follow-up plan, and how to test timing on your own list without fooling yourself.

What the data says

There's less solid evidence on send times than the number of articles suggests. Most figures come from email tool vendors analyzing their own users' emails. They're still useful, as long as you know what they measured.

Put together: send on weekdays, during working hours, earlier in the week rather than Friday afternoon, and expect most replies on the same day. Beyond that, the evidence doesn't support precise rules like "Tuesday at 10:17".

Starting points by type of recipient

These are practical starting points to test, not data. Adjust them to how your buyers actually work.

How to schedule for the recipient's time zone

1. Find where the person works. Use their company's address or their LinkedIn location, not the company headquarters if they're based elsewhere.
2. Convert to your time. Remember that the 50 states span six time zones, and that Arizona (except the Navajo Nation), Hawaii and several territories don't observe daylight saving time. The gap between you and them can change twice a year.
3. Schedule the send. Most email clients and sending tools have a scheduled send option. Set it in the recipient's local time where the tool allows.
4. Spread the volume. Send in small batches over the morning instead of all at once. A sudden burst from one mailbox looks like spam to mailbox providers.
5. Avoid the obvious bad days. Federal holidays, the day after Thanksgiving and the last week of December, when many inboxes go unread.

How many follow-up emails to send

Plan two or three follow-ups after the first email, each adding something new, then stop. Because most replies arrive within a day, wait two to three business days before the first follow-up, and space the later ones further apart.

Stop at any point if they reply, opt out or tell you it's not relevant, and process opt-outs within 10 business days, which CAN-SPAM requires. Never send a follow-up that only says "just bumping this". For wording, see the cold email follow-up templates.

Worked example: a cleaning company across two time zones

Illustrative example. The company, people and numbers are fictional, to show the method.

Summit Commercial Cleaning (summitclean.example) is based in Chicago and sells to property managers of office buildings in Dallas and Phoenix. Its owner wants each first email to land at 10 a.m. local time on a Tuesday.

The time zone arithmetic:

Chicago and Dallas move together. Phoenix stays on Mountain Standard Time all year, so in summer it lines up with the West Coast and sits two hours behind Chicago. Scheduling the Phoenix batch at the same Chicago time all year would land it at 9 a.m. in winter and 8 a.m. in summer, before many property managers are at their desks.

The sequence for one prospect: first email Tuesday 3 November, 10 a.m. Phoenix time; follow-up 1 Friday 6 November with a short example of a building of similar size; follow-up 2 Thursday 12 November with a one-page checklist for nightly cleaning specs; last email Thursday 19 November, a week before Thanksgiving, asking whether someone else handles cleaning contracts.

What the owner measured after two months: 1,200 first emails, 41 replies (3.4%). Of those 41, 23 came to the first email and 18 to a follow-up. Had Summit stopped after one email, it would have had 23 replies instead of 41. The follow-ups added 78% more replies, which is in line with the published outreach data.

Timing won't rescue a weak list or a generic message. If replies are low at every time of day, the problem is upstream: how to write a cold email covers the message, and Bebop can rebuild the list by finding companies that match your best customers and explaining why each fits.

How to test send times on your own list

You can test timing, but you need more emails than most people expect. To tell two reply rates apart with reasonable confidence (95% confidence, 80% power), you need roughly this many emails for each send time:

Even a 50% improvement (4% to 6%) needs about 1,900 emails per variant before you can trust it. A rep sending 200 cold emails a week would need more than four months to test just two send times. That's why timing is usually the last thing to optimize, after the list and the message, where the differences are bigger.

How to run the test if you have the volume:

1. Split one list randomly into two groups, so neither group is better than the other.
2. Send the same email to both, changing only the send time.
3. Count replies (not opens, which are unreliable because of privacy features in some email apps) for at least five business days.
4. Only call a winner once both groups reach the sizes above.

Self-check

• Every email is scheduled in the recipient's local time, including Arizona and other places that don't change clocks.
• You send on weekdays and avoid Friday afternoons and holidays.
• Your follow-ups are planned, dated and each adds something new.
• You stop after the last follow-up, or at once if someone opts out.
• You judge timing tests on replies, with enough emails per variant.

Common mistakes

• Sending everything at your own 9 a.m. West Coast prospects get it at 6 or 7 a.m., under a pile of overnight email.
• Trusting a "best time" from one study. Vendor data reflects its own users. Use it as a starting point and test.
• Calling a test after 100 emails. At typical reply rates, the difference you see is mostly noise.
• Following up the next morning. Most replies come the same day. Give people two or three business days.
• Following up forever. After three or four touches without a reply, stop and move on.

Next step: write follow-ups worth sending with the cold email follow-up templates.