Send your emails at the perfect time with Send Time Optimization

Send Time Optimization answers the question of when to send emails with one simple answer. Read more...



As an email sender, one of the questions you might be pondering is, “when is the best time to send my email campaign?” Is it late morning, early afternoon, early evening? If you throw that question in a Google search, you’ll likely find articles that suggest any of those times are optimal time ranges, but the truth is – it depends. 

We’re all unique individuals, with individual habits. Some people might check their email early in the morning before heading into work, some may check their email during their lunch break, while others might check it after they get home in the evening. With that in mind, it’s naive to apply a blanket solution to a variable problem.

So, how can you make sure your email’s in the inbox at the right time?

Mailgun’s new Send Time Optimization feature is here to help!

What is Send Time Optimization (STO)?

STO uses machine learning to determine the best time to deliver a message to each recipient, at the moment when it’s most likely to be seen and read. The idea here is to deliver a message right before a recipient typically checks their email. From there, the message will be at the top of the inbox, and the user will be more likely to engage with it, thus improving your overall engagement rates and ultimately increasing your ROI.

Sign Up

It's easy to get started. And it's free.

See what you can accomplish with the world’s best email delivery platform.

How does it work?

Mailgun sends billions of messages a month to people around the world, and many of these recipients are subscribed to multiple senders on our platform, which means we have substantial data about their engagement behaviors (how many times, and at what times, that person opens or clicks a message.)

When you send a message using STO, our algorithm analyzes the data we have on hand for a given recipient to identify the optimal time to deliver to that particular inbox. Our sending pipeline then holds on to that message until the determined time, at which point we will deliver the message.

What’s in it for you?

Reach your subscribers

You already know that personalizing an email message to the recipient, using names, personalized content, subject lines, are all hallmark best practices for landing in the inbox. Now, STO adds an additional personalization to the portfolio, allowing you to better cater your messaging to those you want to reach.

Higher engagement

Mailbox providers like Yahoo, Outlook, and Gmail closely monitor how your subscribers interact with your emails to determine inbox placement, making engagement a critical part of your overall email deliverability strategy. For sophisticated senders, STO can help you win additional engagement percentage points by making your messages more visible.

During our STO Beta, our users saw an average of 10% uplift in open rates. Some senders even achieved up to a 25% increase in clicks.


Ease of use

Through the use of machine learning and automation, Send Time Optimization dramatically simplifies the task of personalized scheduling of message sending. No longer do you have to worry about when to send or find the optimal time for the majority of your email list, STO takes out the guesswork.

How can I get started with STO?

Send Time Optimization is available now for our Scale and custom plans. If you’re interested in learning more, feel free to reach out to our sales team or check out our pricing for more details.

Sign Up

It's easy to get started. And it's free.

See what you can accomplish with the world’s best email delivery platform.

Related readings

Nine tips to keep emails from Gmail’s Promotions tab

The Gmail Promotions tab – some people love it, some people hate it, and some people love to hate it. For many of us email marketers, when we find our witty subject lines and...

Read more

Email bounces: What to do about them

There are all sorts of reasons why an email might fail to be delivered and bounce back to the sender (also known as an SMTP Reply). Most of these reasons lie outside of your...

Read more

The BIMI email specification: Your reward for solid authentication

Remember in grade school when you’d get a gold star for a job well done? How about the feeling you get when you earn a new badge on GitHub? It’s always cool to get recognized...

Read more

Popular posts

Mailgun iconSee what you can accomplish with the world's best email delivery platform. It's easy to get started.Let's get sending
CTA icon Mailgun Icon