Send time optimization: What it is and why it matters

As they say, timing is everything. However, while familiar “best practices” still circulate (send on a Tuesday, avoid evenings, never hit send at 5 pm), they rarely reflect how real people behave.

Customers check emails at different times, on different devices, for different reasons. That’s where send time optimization comes in and is particularly useful for your email marketing strategy.

This guide explores what send time optimization is, why it works, how Braze does it differently and what marketers can expect from taking a smarter, data-driven approach to timing.

Contents

• What is send time optimization?
• Why email send time optimization matters
• Debunking the "perfect send time" myth
• How send time optimization works
• Three Case studies that show smarter timing and stronger results
• The long game: Why send time optimization matters for personalization at scale
• Final thoughts
• FAQs

What is send time optimization?

Send time optimization analyzes users’ past behavoir to send messages when they are most likely to engage. Instead of relying on a static send time or guesswork, send time optimization helps find the sweet spot for each individual on your list.

While it's most often used for email, send time optimization can also support channels like push notifications and SMS.

Why email send time optimization matters

Traditional batch and blast sending delivers the same message to every recipient at the same time. It’s simple, but it ignores the nuance of individual behavior. Some people open emails over breakfast, others on their commute, and plenty scroll late at night. That diversity makes a one-size-fits-all send strategy inefficient at best and disruptive at worst.

Send time optimization, and specifically email send time optimization, adapts to each user’s habits. It uses smarter timing to maximize the odds of engagement.

Timing alone can drive meaningful differences. A morning campaign might see a 30% open rate, while the same message in the afternoon barely gets noticed. But those differences aren’t about the clock—they’re about the customer.

Debunking the "perfect send time" myth

Marketers have long searched for a golden rule: Send at 10 am on Tuesday! Avoid weekends! But these broad-stroke rules rarely hold up across a growing, global customer base full of savvy consumers.

Here are a few send time myths send time optimization helps unravel:

• “Never send on weekends.” The inbox doesn’t sleep. Some people scroll on Saturdays when they finally have a moment.
• “Always send early in the morning.” That might work for early birds, but night owls won’t bite.
• “Avoid Friday afternoons.” Some B2C audiences can actually be more responsive heading into the weekend.
• “Stick to a consistent send time.” Habits shift, so shift with them.
• “Avoid sending at 5 pm” Some people unwind by clearing their inbox after work.

Instead of sticking to guesswork, send time optimization reads the data. It spots when users typically engage and predicts the best time to deliver your message.

How send time optimization works

So, how does send time optimization actually work? It’s about using data to time each message to the moment a user is most likely to engage. That means higher open rates, more meaningful interactions and fewer wasted sends.

For example, Braze Intelligent Timing calculates the optimal send time based on a statistical analysis of your user’s past interactions with your app, and their interactions with each messaging channel. The following interaction data is used:

• Session times
• Push Direct Opens
• Push Influenced Opens
• Email Clicks
• Email Opens (excluding Machine Opens)

Three case studies that show send time optimization leads to stronger results

OneRoof: 218% increase in clicks with Intelligent Timing

OneRoof, a property platform, helps New Zealanders buy, rent, and sell homes more confidently.

The problem: OneRoof needed to improve engagement across its marketplace experience. Static send times and disconnected messaging tools made it difficult to reach users at the right moment, leading to missed opportunities.

The solution: After implementing Braze, OneRoof used Intelligent Timing to optimize email delivery windows for each individual user. By adopting send time optimization and pairing it with personalized emails and in-app messages powered by machine learning, the team was able to deliver more relevant content, right on time.

The results: OneRoof saw a 23% increase in email click-to-open rates using send time optimization, a 57% uplift in unique clicks, and a 218% increase in total clicks to property listings. These gains were part of a broader transformation that also drove 50%+ year-over-year user growth.

foodora: Higher conversions and fewer unsubscribes with send-time optimization

foodora is a leading food delivery service, operating across several international markets.

The problem: foodora needed a comprehensive customer engagement platform to unify their communication and improve engagement. Relying on multiple systems without predictive capabilities led to inconsistent messaging, missed opportunities, and higher churn.

The solution: foodora hypothesized that moving from fixed campaign schedules to send time optimization would improve engagement. After onboarding with Braze, they tested Intelligent Timing during onboarding flows for new customers in Austria.

The results showed that delivering messages at more considerate times led to better engagement and lower unsubscribe rates. Encouraged by this, foodora began expanding Intelligent Timing to additional regions and channels, including SMS.

The results: foodora saw a 9% increase in email click-through rates for the group that received messages through Intelligent Timing. They also achieved a 41% conversion rate, a 26% reduction in unsubscribe rate, and a 6% uplift in direct push opens. Based on the success of this experiment, foodora expanded its send time optimization strategy across regions and channels.

KFC Ecuador: 15% lift in email opens with Intelligent Timing

The KFC brand has 22,000+ worldwide locations in more than 150 countries—including Ecuador, where the brand has 148 locations and is hugely popular for its tasty chicken.

The problem: KFC Ecuador’s 100 restaurants were already successful, but their marketing teams lacked a detailed understanding of customer behavior. They needed better insight into regional preferences, channel performance, and the reasons why downloaded coupons weren’t being redeemed.

The solution: Using Braze, KFC Ecuador tested multiple message variants with value-added offers like free delivery and menu items. They compared email versus push and used Braze Intelligent Timing to reach users during their highest engagement windows, boosting visibility and redemption rates.

The results: KFC Ecuador saw a 15% increase in open rates after implementing Intelligent Timing.

The long game: Why send time optimization matters for personalization at scale

Send time optimization isn’t just a quick performance win–it’s a long-term strategy for scaling personalization across your marketing program. Rather than relying on guesswork or batch schedules, send time optimization helps brands align with actual user behavior and preferences.

In a study by Mckinsey, they asked shoppers to create mobile diaries of their personalized interactions with various brands over two weeks. This is what consumers said they wanted from brand interactions:

1. “Give me relevant recommendations I wouldn’t have thought of myself.” Customers appreciate being recommended products or services that complement what they’ve already browsed or bought.
2. “Talk to me when I’m in shopping mode.” A message’s timing is just as important as its content.
3. “Remind me of things I want to know but might not be keeping track of.” Brands can become relevant to shoppers by tracking events and circumstances.
4. “Know me no matter where I interact with you.” Customers expect communications that seamlessly straddle offline and online experiences.

Send time optimization plays a huge role in these consumer desires, helping brands to:

• Build long-term relationships through relevant, timely outreach
• Reduce message fatigue and unsubscribes by aligning with user intent
• Scale personalization across millions of users without manual setup

And because send time optimization gets smarter over time, your campaigns become more efficient, not more complex.

Final thoughts

Sending at the same time to everyone no longer cuts it. With send time optimization, timing becomes a tool for relevance—helping your messages land when they matter most.

Whether you're optimizing for one campaign or scaling personalization across millions of users, send time optimization makes smarter sending simple.

Send time optimization FAQs

What is send time optimization?

Send time optimization is a method of using behavioral data and machine learning to predict the best time to send a message to each individual user. It increases the likelihood of engagement by aligning message delivery with each person’s real habits and preferences.

Is 5 pm a bad time to send an email?

The idea that 5 pm is a bad time to send an email is a common myth. For some users, it might actually be the ideal time, especially if they check emails after work. Send time optimization helps identify and adapt to these personalized patterns.

Does send time optimization work?

Yes, send time optimization works. Brands that use send time optimization typically see improved engagement rates, including higher opens, clicks, and conversions, by delivering messages when users are most likely to interact.