A weekday send around 10 a.m. is enough to get started. MailerLite measured 2,138,817 campaigns sent between December 2024 and November 2025 (United States, United Kingdom, Australia, Canada). At each day’s peak hour, the 7 days of the week are separated by only 1.2 points of open rate. The all-day average stays between 46.5% and 47.5%. This guide gives you a starting slot, explains why the “best days” in different studies contradict each other, then shows how to find the right one for your list in 4 sends.
The best day to send an email: baseline numbers
The table shows each day’s open rate at its peak hour in the 2026 MailerLite study.
| Day | Open rate at peak | Peak hour |
|---|---|---|
| Monday | 49.4% | 10 a.m. |
| Tuesday | 48.7% | 10 a.m. |
| Wednesday | 48.5% | 11 a.m. |
| Thursday | 49.2% | 9 a.m. |
| Friday | 49.7% | 6 p.m. |
| Saturday | 48.9% | 9 a.m. |
| Sunday | 48.9% | 9 a.m. |
Friday (49.7%) comes out on top. Wednesday (48.5%) is last, 1.2 points lower, a relative gap of 2.5%. Over the whole day, MailerLite sees open rates that stay between 46.5% and 47.5% all week. The weekend does not collapse. Guides that name Tuesday as the ideal day therefore rely on a gap this data does not confirm. The panel also comes from a single email tool: it describes that tool’s customers, not your list.
Send time: opens peak in the morning, clicks in the evening
Opens cluster between 8 a.m. and 11 a.m. on weekdays. Clicks follow a different curve: they peak between 8 p.m. and 9 p.m., with Friday at 6 p.m. as the exception. On clicks, Friday reaches 8.09% and Tuesday 7.84%, a 0.25-point gap.
Pick the hour based on the action you want. An email that asks for careful reading or a click to a signup page is worth testing in the evening. An event reminder or an expiring offer gets read in the morning.
Why open rate no longer settles the question
Apple Mail Privacy Protection, launched in September 2021 with iOS 15, preloads messages on Apple’s servers. The tracking pixel, a 1×1 pixel image, fires even if nobody read the email. A 1-point gap between two days drowns in that noise. Mailchimp explains the mechanism in its Mail Privacy Protection FAQ.
MailerLite recommends separating time slots by click rate. The same logic applies to your list: look at your click-through rate and the rest of your email KPIs before drawing conclusions. The open rate has been losing its reliability for several years.
B2B or B2C: match the slot to your audience
Subscribers do not read email at the same moment, because their daily routines differ. Students and executives share neither the same days nor the same hours. Your CRM or email tool already knows who clicks at what time: export that report before inventing a schedule. Then build your personas and segment your list so you can test one slot per segment.
Here are a few starting hypotheses to validate with your own sends. A B2B offer performs during office hours. A travel or leisure offer reads better in the evening or on weekends. None of these hypotheses comes from a study cited here: they only help you choose the first slot to test. For a mixed list, create one segment per type of recipient: business addresses on one side, personal addresses on the other, then compare their clicks on Tuesday at 10 a.m. and Saturday at 9 a.m. The email domains (company or consumer) are enough to tell them apart in most tools.
Multi-country lists: time zones change everything
An email scheduled for 10 a.m. in Paris (UTC+1 in winter) lands at 4 a.m. in New York (UTC-5 in winter) and at 6 p.m. in Tokyo (UTC+9). On an international list, a single slot only serves the country you are in. You can build one segment per country with its own schedule, or use time-zone-based sending when your tool offers it. MailerLite, for example, has this delivery mode: each reader receives the newsletter at the same local time.
Find your slot in 4 sends
An industry average does not replace your own history. Start by exporting clicks by hour for your last three campaigns: that history shows which two slots to pit against each other. Then follow the simplest protocol, which takes 4 sends over 2 weeks.
- Choose one homogeneous segment and keep the content identical across all sends.
- Split the list into two randomly drawn halves. At an 8% click rate, you need about 5,000 recipients per half for a 1-point gap to stand out from chance (a 1.1-point margin at 95% confidence). With 1,000 per half, only a gap above 2.4 points is readable. Below that volume, pool several sends before drawing conclusions.
- Send the first half on Tuesday at 10 a.m. and the second on Thursday at 8 p.m., using your tool’s A/B test if the sends have to go out at the same time.
- Compare click rates after 48 hours, then repeat the test with two other slots.
Example with a B2B list of 10,000 addresses: 5,000 contacts get the campaign on Tuesday at 10 a.m., 5,000 on Thursday at 8 p.m. After 48 hours, you pull 4 numbers per half: emails delivered, unique clicks, click rate, unsubscribe rate. If Thursday evening wins by one click point but doubles unsubscribes, the gain is not real. Then rerun the test with the winning slot against a third time, for instance Wednesday at 2 p.m.
Keep your sending frequency constant during the 4 sends. Changing the rhythm mid-test skews the comparison. Log each test result in a dated spreadsheet (Google Sheets or Excel): in 6 months, your own history will be worth more than any panel study.
Common pitfalls in a send-time test
The first pitfall is changing the subject line from one send to the next. You can no longer tell whether the gap comes from the hour or the content. The second is drawing conclusions from a single send.
The last is comparing different segments. A segment of active customers clicks more than a segment of people who signed up six months ago, whatever the hour.
Frequently asked questions
Should you avoid weekends?
MailerLite’s data puts Saturday and Sunday at 48.9%, 0.2 points below Tuesday. Test it on a consumer list before ruling it out.
What time is best for a newsletter?
Mornings between 9 a.m. and 11 a.m. maximize opens, and evenings around 8 p.m. target clicks. Your 4-send test settles it.
Should you send at each recipient’s local time?
Yes, if your list spans several time zones and your tool can do it. Otherwise, segment by country. Schedule one send per segment at 10 a.m. local time, with an interval of at least 1 hour between two countries so you can watch the first results before launching the next.
A good slot cannot rescue a dirty list
The best send time is useless if the message never reaches the inbox. Since February 1, 2024, Gmail has required senders of more than 5,000 messages a day to meet the following rules (Yahoo aligned on the same date): SPF, DKIM and DMARC in place, one-click unsubscribe (List-Unsubscribe and List-Unsubscribe-Post: List-Unsubscribe=One-Click headers, per RFC 8058), and a spam rate below 0.30% in Postmaster Tools. Google recommends staying below 0.10% (Google’s bulk sender guidelines). For the details, see Gmail’s sender requirements and the complaint rate.
A list that contains invalid addresses produces hard bounces. Those bounces damage your sender reputation before the send time even comes into play. Compare your rate with what platforms tolerate, then run a sample of your list through a verification tool before the first send of the test. The ideal checking rhythm is covered in the article on how often to verify an email list.
