You've asked it. Your boss has asked it. Some agency has probably charged you to ask it. How often should we be emailing our list?
You google it. You get answers ranging from "once a week, max" to "three times a day if your content is good enough." You read a case study from a brand that swears daily emails saved their business. Then another from a brand that swears cutting frequency in half was the best move they ever made. Both can't be right. Except they can.
Here's the thing nobody wants to tell you. The answer to email frequency is sitting in your Klaviyo account right now. It's just not in any of the reports you usually open.
Why the generic advice fails
Every "best practice" article on email frequency makes the same mistake. It assumes your list is everyone else's list. It isn't.
Your subscribers came in through specific channels. They have specific buying patterns. They opted in for specific reasons. A brand selling consumable skincare can email twice a week and still feel relevant, because customers actually use up the product and need to buy again. A brand selling $400 jackets cannot, because most people aren't buying a new jacket every six weeks no matter how good the email is.
So when someone tells you "two to three times a week is the sweet spot," what they're really saying is "for some hypothetical list that isn't yours." That advice has the same value as a stranger telling you what to name your kid.
The metrics that actually answer the question
Forget open rate. It's broken and you know it. Apple Mail Privacy Protection cooked that metric in 2021 and we've been pretending otherwise ever since.
Here's what you should actually be watching:
Unsubscribe rate by send. Not the campaign average. Each individual send. If you bump frequency from once a week to twice a week and your second weekly send consistently has a 50% higher unsubscribe rate than the first, your list is telling you something. They didn't sign up for that second email. Learn more about why your unsubscribe rate threshold might be misleading.
Spam complaints.This one matters more than people think. Anything above 0.1% on a single send and Gmail starts throttling you. Above 0.3% and you're in real trouble. If complaints climb when you raise frequency, you've got your answer and it's not "send more."
Revenue per recipient over a rolling window.Look at total email revenue divided by unique recipients across a 30-day window. If you go from sending eight emails that month to twelve and your revenue per recipient drops, you're cannibalizing yourself. The extra sends aren't generating new revenue. They're just spreading the same revenue across more emails while burning attention.
Engaged subscriber count over time. Pick a definition (clicked or opened in last 60 days, with apple caveats noted) and track the absolute number weekly. Healthy programs grow this number even as the list grows. If yours is flat or shrinking while your list grows, your frequency is outpacing what people want. You can calculate list fatigue before the unsubscribe spike hits.
How to actually test it
The right way to figure out your frequency is to run a real test, not read another article.
Take your list and split it into two random groups of equal size. Send group A your current cadence for 60 days. Send group B one additional email per week for the same 60 days. Make sure the extra email is similar in quality to your normal sends. Don't make it junk and then conclude that "more emails hurt revenue." The test is about frequency, not content quality.
At the end of 60 days, compare:
- Total revenue per recipient
- Unsubscribe rate
- Spam complaint rate
- Click rate trend (not absolute, but the trajectory across the period)
If group B made more money and the negative metrics didn't blow up, you have permission to send more. If group B made the same or less money and unsubscribes climbed, you have your answer in the other direction.
Then do it again, in the other direction. Maybe you're sending too much. Take group A down to one less email per week and run the same test.
This is boring work. It takes months. That's why most teams don't do it. They'd rather argue about it in a Slack channel and then default to whatever felt right last quarter.
The harder question underneath
Most "we need to send less" conversations aren't actually about frequency. They're about content. When you have nothing to say, every email feels like too many.
Ask yourself, honestly, would your most engaged customer be sad if they missed any of your emails this month? If the answer is no, frequency isn't your problem. You're sending forgettable emails. The fix isn't sending fewer. The fix is making the next one matter.
The same goes the other direction. Brands that legitimately can email five times a week without burning out the list are usually the ones whose customers actually want to hear from them. Their content is genuinely useful, entertaining, or both. Frequency is downstream of quality.
What this looks like in practice
A reasonable starting point for most DTC brands is two to three sends per week to engaged subscribers, one to two per month to disengaged. But that's a starting point, not an answer. If your list is already showing signs of fatigue, read our guide on how to fix a burned-out email list in 90 days.
From there, you watch the numbers. Every quarter, you ask:
- Is revenue per recipient flat, growing, or shrinking?
- Are unsubscribes per send creeping up?
- Are spam complaints in safe territory?
- Is the engaged-subscriber count growing in absolute terms?
If three out of four are healthy, you can probably push frequency. If two or more are deteriorating, pull back. It's that simple. It's also that uncomfortable, because it means you can't outsource the answer.
Where Cadento fits in
One reason teams default to vague frequency rules is that the data needed to answer the question is scattered across reports that don't talk to each other. Send density lives in one place. Unsubscribe trends in another. Revenue per recipient in a third. By the time you've pieced it together, you've got a meeting in five minutes and the answer goes back in the drawer.
Cadento pulls the picture together so you can see your real send pattern, your fatigue indicators, and your revenue trends in one view. You can plan next month knowing what your list actually tolerated last month. That doesn't answer the frequency question for you. But it stops you from guessing.
Try Cadento free and stop guessing what your list can handle.
The takeaway
Nobody on the internet can tell you how often to email your list. Not us, not your agency, not the guy who tweets infographics about email marketing. The answer is in your data and it changes over time as your list changes.
Watch the right metrics. Test in real splits, not gut feel. And if you're tempted to send more, make sure the next email is one your best customer would actually miss.
That's the real frequency rule. Send as often as you can stay worth reading.