What our data told us about the best time to send email campaigns

By Ros Hodgekiss on 8th August 2014

Who really waits to get to their desk before reading their email these days? In reality, many people start their workday while walking into the café, or on the train. Or, if you're like 50% of folks, you begin and end your day emailing in bed.

With habits like these, it’s no surprise then that 42% of first opens are made on mobile devices. But to find out more about how we open email today, we looked at data from over 192 million opens, then asked Gary Elphick - a mobile specialist at ideas agency Tongue - for his thoughts. Read on to find out whether the time of day you send is important and whether you can improve your results by rethinking when and what you send.

When do opens occur?

First of all, knowing when to send really means knowing your recipients and their behaviours. So, do you know what time of day do people read their emails, how much time they have to do so and how exactly they spend that time? Here's when we observed people opening their email:

% Email Opens by Hour

% Email Opens by Hour

Based on email campaigns sent worldwide, October 2013. Time zones were factored into the analysis and are set to that of the email sender.

To make more sense of the above, we decided to have a look at what time of day emails were opened, based on the typical workday of getting up, going to work, then going home:

Hours of the day% Emails Opened
Midnight - 8am (before work)16%
9am - 5pm (minus lunchtime)53%
1pm (lunchtime)7%
6pm - 11pm (after work)24%

As can be expected, the pattern of opens increases as people begin to wake up and start their day, then subside again dwindle as they go to sleep. But it's worth highlighting:

  • Workday hours (9am - 5pm) are when over half of all email opens happen
  • Peak open times are just before and after lunch
  • Lunchtime opens only drop by a fraction
  • Including lunch, 47% of emails are opened outside of work hours. Note is that the majority of these "non-working" opens occur on mobile devices

Talking about devices, we also looked at which environments opens over time were happening:

% Email Opens by Device by Hour

% Email Opens by Device by Hour

From this, it's clear that there's a relationship between time of day and the platform you use to open your email. Based on hour of the day, email opens on mobile and desktop environments have an inverse relationship. Before work and after hours, emails are opened on mobile phones and desktop opens decline. During work hours, desktop opens increase and mobile opens decrease. This might seem fairly obvious, given that you're likely to read your email on the train or bus commute to work (please don't read emails while driving!), then switch to your desktop, or laptop when you get to your destination. However, it's interesting to see the data back this up.

How do I optimize my email campaigns?

So, while it seems that we should be planning around the 9am "email rush", the truth is that there is really no ideal time - after all, almost half of emails are opened outside of work hours. So, how about optimizing what we send, instead of when?

we need to be thinking in the same "time windows"For insight into this, we called on Gary Elphick. As email marketers, Gary suggests we need to be thinking in the same "time windows" as our subscribers; being the different periods interacting with emails, depending on the device. These windows are:

  • The 3 minute window, when you're most likely opening email on a mobile device. For example, when waiting for coffee at your local, you have just about enough time for a quick scan of new emails, to forward on any urgent tasks and to take note of anything that needs to be revisited later when you have more time.
  • The 5 minute window, when you're most likely opening email on a mobile device. Say, in a cab between meetings, you have time for a couple of quick email responses, to action urgent items and respond to important people.
  • The 10 minute window, when you could be either mobile or desktop. For example, at lunch you have just enough time to respond to not-so-urgent emails, file things you’ve done and re-read those emails scanned earlier.

To ensure email marketers make the most of their email program spend, Gary offered 4 key considerations to keep in mind, prior to sending:

  • Time of day - What is the best time of day to send your email marketing messages? Can you optimize for the time of day you are sending and the device most likely to open your email?
  • Brevity - How much can someone really read during the 3 minutes they have in the coffee line? Keep your copy to the point and make call-to-actions as clear as possible
  • First words - The first words of your campaign in your subject line are incredibly important content, so craft them with thought.
  • Mobile first - With mobile email open rates at 42% and growing, we need to optimize our email marketing for a mobile first environment. Also, remember to test your landing pages on mobile; having someone tap through, only to end up on an unusable landing page is a terrible experience.

Many thanks to Gary for sharing his practical advice with us. Check out his work at Tongue and also DisruptSurfing. Now, it's over to you - do you have a send time that works best, or a technique that works? Let us know in the comments below.

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8 Comments

  • Dan
    9th August

    “So, how about optimizing what we send, instead of when?” - this Is the best approach, I think. Inboxes are very busy these days and only relevant content will be a game changer.

  • Chris Sargent
    11th August

    Thanks for this. With this being the case, it seems that we should probably think about optimising regular email signatures for mobile devices. Do you have any articles or guidance on that?

  • Paul West
    11th August

    Hey Chris, thanks for your comment! We haven’t written any articles specifically on email signatures I’m afraid. The email program you are sending from will have a big impact on what’s possible and I think the best advice right now would be to keep your signature as small and simple as possible to ensure it looks okay on mobile devices.

  • Skipfish
    11th August

    Aside from the first words of the subject line, the first line of an email must capture the reader’s attention. Yes youve gotten them to open your email—now what?

    We also find they putting just 1-2 clear, well-defined calls-to-action work best. :)

  • Pieter Bezuijen
    12th August

    Great article!
    Did you look at differences in target groups? For example the difference between business-to-consumer and business-to-business e-mail campagnes? With the little data we have, we see huge difference in mobile opens when comparing b2b versus b2c campaigns (b2b campaigns have far less mobile opens in our experience). That could have an impact on both sending times and opening windows.

    Small tip: the last link to the Tongue website doesn’t work, there’s a typo in the href ;-)

  • Ros Hodgekiss
    13th August

    Hi Pieter, at this point no - but I think comparing B2B and B2C campaigns would make a fantastic study! Really interesting that you spotted a difference here and we’ll certainly take this into account next time we look into email behavior.

    Oh, thank you for picking up that broken link - our mistake! We’ve fixed it now, thanks to your help :)

  • Daniel
    14th August

    I’m still trying to figure it out - what did your data tell you about the best time to send email campaigns?

    As far as I can tell, this is about when people open emails, not the likely success of a campaign depending on when you send it.

    For example, ‘over half of all email opens happen during workday hours’ - maybe over half of all emails are sent during those hours? 7% are opened at lunchtime - would this increase if more emails were sent at lunchtime?

    What does this data tell us we should do?

    What I’d like to see is a comparison of open rates, based on the time the campaigns were sent.

    Or even more interesting - how long it takes to open emails, based on the time they were sent. Then if you find emails sent at 3pm are generally left for 3 hours before being opened, you could potentially change your send time to 6pm to get better results. This would also vary based on different customers though - B2B or B2C.

  • Ros Hodgekiss
    15th August

    Hi Daniel, I’m sorry if I did not provide concrete answers on send times here - in my opinion, doing so would be a distraction from two themes, being:

    - We have to adapt to the behaviors of our subscribers, whether that means reading in 3-minute bursts before work, or after hours in bed
    - There is really no “best” time to send; each of us has to experiment and learn from our respective lists

    That said, I do have some interesting numbers for you. First of all, about 52% of opens happen in the first 6 hours, with ~11% opens happening in the first hour. This means that an email sent in the morning will likely benefit from a stream of opens all day.
    - By this reasoning and our data, if you have a lot of subscribers reading on mobile devices, you’ll likely benefit from sending in the early morning and early evening.

    That said, things get fuzzy if your email recipients are spread out geographically - so again, testing is really key here.

    We’re planning to do a lot more research around send time optimization, so by all means, subscribe to this blog and we’ll likely have some interesting nuggets for you in the months ahead. Thanks for writing in, Daniel - I really appreciate you asking the big questions! :D

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