Why the worst day of the week is the best day to send emails 

Tuesday is the most popular day to send marketing emails for a reason: it consistently delivers the highest open rates across multiple 2025 studies But the best time to send depends on what you want your readers to do.

If you're sending a newsletter or educational content, earlier in the week tends to win. If you want clicks (webinar signups, survey completions, purchases), later in the week and later in the day typically outperform. And the real answer for your specific audience will always come down to testing.

We've pulled together findings from HubSpot, Moosend, Omnisend, and MailerLite to give you a data-backed starting point, then show you how to test your way to the right email sending schedule.

• Tuesday consistently ranks as the best day to send marketing emails across 2025 studies, though Thursday performs nearly as well. Mid-week is your safest bet for open rates.
• Match your send day to your email type. Newsletters and educational content perform best earlier in the week. Action-oriented emails (webinar signups, surveys, product launches) can benefit from later sends when click-through rates climb.
• Evening sends outperform morning sends for engagement. Moosend's analysis of 10 billion emails found click-through rates peak between 8-9 PM, and Omnisend's 2025 research found 8 PM sends reaching a 59% open rate.
• AI-powered send time optimization now lets you personalize delivery for each subscriber based on their individual behavior, increasing open rates by 23% over static timing.
• These benchmarks are starting points. The only send time study that matters is the one you run on your own list.

2025 email benchmarks for reference: The average open rate across industries is approximately 42-43%, though Apple Mail Privacy Protection inflates this number. The average click rate is about 2.09%, up slightly from 2024. The average click-to-open rate is 6.81%. Use these as your baseline when evaluating whether your timing changes are actually improving performance. (MailerLite, "Email Marketing Benchmarks 2025")

What day of the week do you dread? If you said Tuesday, you’re not alone. While the idea of “blue Monday” has been mostly debunked, surveys have found that we experience the most professional and emotional stress on Tuesdays. Supposedly, the pleasure of the weekend allows us to coast over into Monday, but on Tuesday “the reality [of work] sets in”.

But Tuesday might be the best time to send email. According to a 2013 census by GetResponse, people send over 17% of all emails on Tuesday, making it the most popular day of the week to send.

You might expect weekends to perform well since there's less competition in the inbox, but 2025 data from Moosend and MailerLite tells a different story. Saturday and Sunday consistently show the lowest open and click-through rates. Many people simply aren't checking work-related email on weekends. Friday, on the other hand, performs surprisingly well. It may be that people are in a more relaxed, browsing-friendly headspace heading into the weekend.

If you’re a marketer trying to decide the best day to send email, or a lesson in an email course, Tuesday is a sensible default. Take advantage of the high open rates earlier in the week to send emails that don’t necessarily need to drive clicks. Share an update, send out a blog post, or educate your readers.

But if you need help driving clicks or want your readers to perform an action like signing up for a webinar or taking a survey, sending later in the week could work in your favor. The highest CTR actually occurs over the weekend. Email volumes are lower over the weekend and people finally have time read their email.

We've seen this at Customer.io firsthand: some of our best-performing sends have gone out at times conventional wisdom says to avoid. The takeaway isn't that you should start blasting emails on holidays. It's that send time optimization matters at the margins, but it will never save a bad email. The best subject line sent at the perfect time still loses to genuinely useful content sent at an inconvenient hour. If your email is interesting enough, your audience will open it whenever it arrives.

The time of day you send your emails can be just as influential on open rates as the day you send them. You might have learned to send your emails in the morning. However, this may not be the best strategy for your newsletter or on-boarding emails.

While most people check their emails in the morning, they’re usually trying to start their day on a productive note. This means anything unnecessary will likely be trashed or archived without being read. While your newsletter is valuable, it can easily fall by the wayside in the face of work-related stress in the morning. This could explain why the highest email open rates are actually in the afternoon and evening.

The conventional wisdom says send in the morning, but 2025 data supports the opposite for engagement. Studies found that email click-through rates peak between 8-9 PM, with Monday at 9 PM hitting a 9.01% CTR. Omnisend's 2025 research found even more dramatic results for opens: 8 PM sends reached a 59% open rate compared to 45% for 2 PM sends.

The pattern makes sense when you think about your own behavior. During the workday, you're triaging your inbox and archiving anything that isn't urgent. In the evening, you're settled in, less rushed, and more willing to actually read a newsletter and click through to something interesting.

Everything above gives you a strong starting point for your email sending schedule, but to reach the next level, start personalizing send times at the individual level. AI-powered send time optimization analyzes each subscriber's behavior (when they open, what device they use, how often they engage) and delivers your email at the moment that specific person is most likely to act.

The companies getting the best email engagement in 2025 aren't sending to everyone at 10 AM on Tuesday. They're sending to each subscriber at the time that individual is most likely to engage. Customer.io lets you trigger messages based on individual user activity and behavioral data rather than blasting your entire list at a single "best" time. If you're still using a one-size-fits-all sending schedule, you're leaving engagement on the table.

These strategies are a good place to start, but they won’t help you if they don’t serve your audience. Know who you’re writing for. Are your readers busy entrepreneurs who want to check their email over lunch, or small business owners who get home late? Is your content work-related? Or is it for leisure time? You should adjust your email timing to better meet your audience’s needs and fit in with their schedules.

The timing of your emails is a critical component of your email lifecycle campaign. But while these strategies might help you get started, every small business is unique. If you take away one thing from this post, let it be this: test to figure out what works best for you. It might take a few months, but you should feel free to play around with the days and times you send your emails to find out what succeeds. Run different campaigns with the same content to see what scheduling works best. Take note of the emails that get the most clicks, then send your subsequent campaigns following the new timeline.

Ready to start scheduling emails with a best-in-class platform? Try Customer.io free for 14 days.

Is Tuesday really the best day to send marketing emails? It's the most consistently recommended day across studies. HubSpot's 2025 research found that 27% of US marketers report Tuesday as their highest engagement day, and Moosend's analysis of 10 billion emails ranks it in the top two for open rates alongside Thursday. But the gap between Tuesday, Wednesday, and Thursday is small enough that mid-week is the real winner. The better question is what type of email you're sending: educational content tends to perform well earlier in the week, while action-oriented emails can benefit from sending later.

What time of day gets the highest email open rates? It depends on the study, and 2025 data challenges the old advice. Traditional wisdom says morning (8-11 AM) is best because that's when people check their inbox. But Omnisend's 2025 analysis found that 8 PM sends reached a 59% open rate, significantly higher than the 45% for 2 PM sends. The likely explanation: there's less competition in the inbox at night, so your email is more visible.

When should I send emails if I want people to click? Evening. Moosend's 2025 data shows click-through rates peaking between 8-9 PM, with Monday at 9 PM hitting a 9.01% CTR. People open emails in the morning when they're triaging their inbox, but they click through and take action at night when they have time to actually read and explore.

Should I send marketing emails on weekends? Generally, no. 2025 data from Moosend and MailerLite shows Saturday and Sunday consistently have the lowest open and click-through rates. The exception: if you're in B2C or retail and your audience shops on weekends, test it. Friday actually performs surprisingly well, possibly because people are in a more relaxed, browsing-friendly mindset heading into the weekend.

What is send time optimization, and should I use it? Send time optimization uses AI to analyze each subscriber's individual behavior (when they open, what device they use, how often they engage) and delivers your email at the moment that specific person is most likely to act. Campaign Monitor found this increased open rates by 23% over static best-practice timing. If your platform supports it, it's worth turning on. Customer.io lets you trigger messages based on individual user activity rather than blasting your entire list at the same time.

How long should I test before settling on a send time? Give each variation at least a few weeks. Run A/B tests with identical content sent at different times or on different days. You need enough volume to reach statistical significance, so smaller lists may need a longer test window. Test one variable at a time (day or time, not both simultaneously) so you can isolate what's making the difference.