Best time to send cold emails: what 850M emails show
Send between 6 and 10am in the recipient's time zone. The hour beats the day: 1.34% replies at 7am vs 0.82% at 4pm.
Send cold emails between 6 and 10 in the morning, in the recipient's time zone, on any weekday. That is the short answer, and the hour matters far more than the day. Smartlead's data on more than 850 million emails shows a 7am send earning 1.34% replies against 0.82% at 4pm. The spread between the best and worst weekday in the same data is under a tenth of a percentage point.
Most "best time to send" advice still leads with "Tuesday at 10am." The newer, bigger datasets disagree with half of that. Below is what three large vendor studies found, where they contradict each other, and a sending schedule you can set up today.
What the data says about the time of day
Smartlead published reply rates for every hour of the day, measured in the recipient's local time. The pattern is blunt: replies jump at 6am, peak at 7am, stay high until 10am, then slide. From 1pm to 11pm every hour sits between 0.78% and 0.86%.
Cold email reply rate by send hour, recipient's local time
Put in contacts instead of percentages: at 7am you need about 75 people to get one reply. At 4pm you need 122. Same list, same copy, same mailbox. Only the clock changed.
Belkins ran its own study on 7.5 million cold emails sent through its campaigns from January to November 2025 and landed in the same place. Its morning window (8am to noon) had the best reply rate at 0.54%, early morning (5 to 8am) was close at 0.52%, and the afternoon fell to 0.47%. The afternoon was also where most emails were actually sent. That is the part worth sitting with: the most common send window in the industry is one of the worst ones, mostly because that is when SDRs are at their desks and hit "launch."
Belkins also tracked booked meetings, not just replies. Morning and early-morning sends both converted to meetings at 0.4% of emails sent. Every other window sat at 0.1%. Treat that ratio as directional rather than exact: the published meeting rates are rounded and come close to the reply rates, which suggests a narrow slice of campaigns drives them. But the direction agrees with the reply data, and that is enough to act on.
Does the day of the week matter?
Less than you have been told. Here is how the three studies line up:
| Study | Best day | How big is the gap |
|---|---|---|
| Smartlead, 850M+ emails | No clear winner | 0.82% to 0.91% across the week |
| Belkins, 7.5M emails, 2025 | Wednesday and Thursday, 0.48% | Mon and Tue 0.45%, Fri 0.44% |
| Instantly, 2026 report | Wednesday | Not published as numbers |
Wednesday shows up near the top in two of three studies. But Belkins found a twist: Wednesday had the highest reply rate and the lowest meeting rate of any weekday, 0.1% against 0.2% for the others. More people answered, fewer of them booked. Their guess is that Wednesday replies skew toward polite "not now" answers.
Two days deserve a separate word.
Friday is not dead, but Instantly reports it brings the biggest wave of out-of-office auto-replies. If you send on Friday, expect to sort through more noise on Monday.
Sunday had the highest raw reply rate in the Belkins data, 0.57%. Do not copy it. Belkins says Sunday volume was tiny and driven by a few senders who deliberately target executives planning their week on Sunday evening. It can work for that audience. It is not a default.
So the honest summary: pick any weekday, prefer Tuesday to Thursday if you have a choice, and spend your attention on the hour instead.
Why mornings win
Nobody has a controlled experiment on this, so here is the practical reasoning rather than a claim.
In the morning people triage. They open the inbox to decide what the day is about, and a short, relevant email from a stranger can make the cut. By the afternoon the inbox is a backlog. Your email arrives under twenty internal threads and a calendar full of calls, and it gets skimmed or skipped.
There is also a position effect. An email sent at 7am is near the top when the person sits down at 8:30. An email sent at 2pm is buried by the next morning, and that is when many people finally clear their inbox.
The time zone mistake that ruins all of this
Every number above is local to the recipient. Smartlead measured hours in the recipient's time zone. Belkins measured the send time and warns that for multi-time-zone lists the local time may differ.
If you are in Berlin and send at 9am to a list in California, your email lands at midnight. If you are in New York and send to London at 9am, it arrives at 2pm, right in the weak window. Most sequencing tools can schedule by recipient time zone if the contact record has a location or a time zone field. Fill that field. If you do not know where someone is, use the company's headquarters as a fallback and split the list by region before you launch.
A sending schedule you can copy
Cold email schedule that follows the data
- Split the list by time zoneOne segment per region, each scheduled in local time. Use company HQ when the person's location is unknown.
- Send first touches 6am to 10am localThe 6 to 8am slice is underused and almost as strong as mid-morning. Spread sends across the window rather than firing them at one minute.
- Use Tuesday to Thursday for launchesA small edge, not a rule. Do not hold a ready campaign until Wednesday.
- Keep daily volume flatMailbox providers trust steady volume. Do not send 500 on Monday and nothing until Friday.
- Send follow-ups in the same windowInstantly reports that follow-ups bring 42% of all replies, so their timing matters as much as the first email's.
- Answer replies within the hourA reply that arrives at 8am and waits until 3pm loses the momentum the morning send created.
A word on that fourth step, because timing advice often breaks it. If you squeeze a whole day's volume into a two-hour window, each inbox sends in bursts. Spread the sends across 6 to 10am with a few minutes between each email, and keep the daily total the same every working day. For how many emails one mailbox can send safely, see how many cold emails per day per inbox.
What timing cannot fix
The gap between 7am and 4pm is real, but it is a gap between 1.34% and 0.82%. List quality and the email itself move results by more than that. A badly targeted list sent at the perfect hour still gets nothing. If your reply rate sits well under the benchmarks in what is a good cold email reply rate, fix the who and the what before the when.
Also remember what these studies are. They are vendor data from vendor platforms, with each vendor's own mix of industries, list sources and senders. None of them is a controlled test. The safest reading is where they agree: mornings beat afternoons, and the day matters little. Then test it on your own list. Send half a segment at 7am and half at 2pm local, keep everything else equal, and compare after a few hundred emails per half.
Where Nitrino fits
Most of the schedule above is configuration you set once in a sequencing tool. The last step is the one that slips: when a reply lands at 8am, someone has to answer it while the person is still at their desk. Nitrino runs campaigns with a separate letter for each person, paces sending by the health of each account, and answers replies in the account owner's voice as they come in, across email, LinkedIn and messengers. It calls a human only when a decision is needed. If that last step is where your morning replies go cold, see how Nitrino works.
