Schedule and deliverability

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It’d be fantastic if every email you sent had a 100 percent open rate. But that’s not realistic. Even so, it’s so important to take every possible step to improve the odds of your subscribers reading your emails, that we spent our entire lesson on inbox presence talking about ways to chase that elusive goal.

In this lesson, we’re going to take a look at the other major reasons your emails are opened—or not: schedule and deliverability. Schedule is all about the timing and frequency of your emails: The best days and times to send, and how often you should be sending. Deliverability is about making sure your emails wind up in your subscribers’ inboxes—not in their spam folders, bounced back to you, or eternally floating lost somewhere in the pipes of the internet.


When to send your emails (date and time)

Before we get into the ideal days of the week and times of the day to send emails, it’s important to note the ideal time varies heavily from industry to industry, business to business, and even customer to customer. That means these tips should be taken less like gospel and more like jumping off points for your own testing—read and digest this knowledge, then segment and test until you find the ideal results for you.

Here are the results from three large-scale studies into the optimum timing of emails. While the findings aren’t quite identical, the similarities are unmistakable.

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The nuances of the studies are a bit different, but there’s broad agreement on a few key points:

  • Weekdays are a far better time than weekends to send emails.
  • Fridays are the shakiest weekday to send.
  • It’s good to send emails in the morning when people are settled in at work and possibly looking for a break.
  • Afternoons can be a decent time to send, but probably not as good as mornings.
  • Nights and the middle of the night are the worst time to send.

Figuring out your ideal timing

It’s tempting just to take the studies’ word for it, set your emails to go out at 10 AM on Tuesday, and not put any more energy into this endeavor. However, as we said at the beginning of this section, the results for your business and customers may vary. While one of the above studies found the ideal time overall was 10 AM to 12 PM, they also found the ideal window extended later for retail brands, when sending to college students, and when sending to recipients in Norway (yes, really). That’s why testing is important.

You can read our lesson on A/B testing for thorough advice on how to set up statistically-significant tests with your email marketing but, in brief, a send timing frequency study could look like this. Send an email to a portion of your list on Monday and an identical email to a different portion of your list on Tuesday. If there’s a notable difference, say Monday had a better open rate, repeat the test, but this time send on Monday and Wednesday. Then repeat the process with different times of day as you zero in on your ideal day of the week and time of day.

Once you have your results, there’s a good case for segmenting by time zone. For instance, if you send your emails so they’re hitting your U.S. east coast customers’ inboxes at 10 AM, that means they’re hitting your west coast customers’ at 7 AM—which is not anywhere close to the ideal zone. And they’re hitting your Hawaiian customers at 4 AM and your Australian customers at 11:30 PM. If you segment your sends by time zone, you can hit every inbox everywhere at 10 AM to hit the peak performance window.

Email frequency

To repeat the same refrain from the previous section: There’s no such thing as a universally-perfect email frequency. However, it’s essential to figure out the correct frequency for your store, since the runaway top reason why people unsubscribe from a list is too many emails.

That said, the solution isn’t to say, “Sending too much is the biggest driver of unsubscribing? No problem, I’ll just barely ever send emails.” That won’t work either. More emails drive more revenue, and people who sign up from your list actually do want to hear from you. Almost two-thirds of subscribers say they want to receive a “promotional email” at least weekly, and almost nine out of 10 want one at least monthly. (That study also found nine percent of people who subscribe to a list never want to hear from it which is… confusing.)

How often customers want to hear from a brand.

There are other problems that come from undersending, beyond the missed revenue opportunities and disappointed subscribers. You reduce your inbox presence, which hurts your brand visibility. You may find a higher complaint rate when you do send as people aren’t accustomed to getting emails from you, so they forget they signed up and report you as spam. And you wind up with a less hygienic list, which can mean more bounces and even falling into spam traps.

So you shouldn’t send too many emails. You shouldn’t send too few emails. What’s the Goldilocks spot where the number you’re sending is just right?

Here are the results of some major studies into email frequency and their conclusions.

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The takeaway from those studies, interestingly, tends to be: Err on the side of sending more, not fewer, emails than you’ve been sending now. It’s also clear that there is industry-to-industry variation. E.g., according to the Zettasphere study, subscribers to fashion brands tend to tolerate a higher email volume than the general average.

Questions to ask as you figure out your ideal frequency

Here are some questions to ask yourself as you figure out the starting point for your ideal email frequency.

How often do you have something worthwhile to email your subscribers? This is the first, and arguably biggest, determining factor behind the correct email frequency for your brand. Since every email you send has to have some type of value to your subscribers—how often do you really have something to say? The frequency of your sends should, ultimately, hinge on the quality of your content.

How often will your customers receive automations? When you plan your email frequency (or lay out an email marketing calendar), you’re likely planning your broadcasts. That means you’re including things like your newsletters, sales and product announcements, and company updates. But those may not be the only marketing emails your customers are receiving from you. What does your automation schedule look like? Are you sending out weekly updates on VIP status? Periodic feedback and review requests? Cart abandonment emails and replenishment reminders? If your customers are regularly receiving automations, that’s something to factor into your send frequency equation. You can exclude most transactional emails, like receipts and shipping notifications, from this calculation, since those are predicated on specific customer action and are expected emails that customers will not view as marketing, even if they may include a bit. 

What do you sell and how big is your company? The ideal frequency for a company’s email marketing depends quite a bit on the company’s fundamental DNA—and what makes sense based on the company’s size and catalog.

For instance, flash sale and daily deal sites that are offering new products and/or discounts on a daily basis can justify daily sends. Of the two-million-or-so brands’ email lists I subscribe to (for research purposes, of course!), the highest frequency comes from the daily deals site Until Gone. They average right around two emails per day—but since they have an endless supply of new products at huge discounts, they can more or less get away with it. (Note: They also don’t use preview text, which we’d highly recommend.)

Frequent emails in an inbox.

Massive retailers with giant catalogs (and giant email lists that can handle lots of churn) can also send at that frequency level. Personality-driven brands, like coaches or experts selling info products, may want to consider near-daily sends as well, since that’s what their fans signed up for. 

Brands with smaller catalogs and smaller followings will have a tougher time justifying such a high frequency send. Luxury and premium brands will also want to avoid such a high frequency, since their brands’ DNA is rooted in exclusivity and selectiveness. And B2B companies will hold back a bit more as well, since being too pushy and overwhelming their business contacts’ inboxes is a turn-off. (Business people are so very busy and important, after all.)

Here are all of the emails I’ve gotten from the niche coffee maker brand Barisieur in a seven-month timeframe. They’re a small, premium brand with basically one product (a high-end coffee maker, plus a few accessories for it). And, thus, they’ve sent 11 emails in eight months—fewer than the aforementioned daily deals site Until Gone sent me in just the past week.

A lower frequency of emails.

What is your competition doing? Even though this probably goes against everything your independent entrepreneurial spirit is telling you, one of the best ways to find a good jumping off point for your email marketing frequency is… measuring your competitors’ email marketing frequency. You should already be subscribing to your competitors’ email lists—it’s important to keep tabs on what they’re doing so you can compete and, theoretically, do everything better. But you can also learn a lot about what the customers in your niche want and expect in terms of email frequency by checking on your competitors. Are they sending daily? Perhaps your customers would expect that—and you might get left in the dust by your competitors if you’re only sending once every few weeks.

The point of this isn’t to take what your competitors are doing and copy it exactly—it’s to use your competitors as a gauge to get a clearer picture of what customers in your space want and expect.

What expectations did you set? Did you set up an expectation of a certain frequency on your signup form or in your welcome email? If you promised “daily deals, ideas, and more” on your email signup form, your subscribers will expect daily emails. If you promised “weekly,” they’re expecting weekly—and might not be very happy if suddenly you’re sending them four emails a week. If you promised “infrequent” or “occasional” emails, that sets up a different set of expectations as well.

A list promising occasional emails.

And if you aren’t offering any frequency expectation at the point of subscribing—once you figure out your ideal send frequency, maybe you should start doing so. That will help future subscribers know what they’re getting from you, which should help reduce quick unsubscribes and unhappy customers.

Finding your ideal frequency

Much like the process with finding your ideal day and time to send, finding your ideal frequency involves testing and monitoring. In this case, it’s gradually increasing the number of emails you send—and pushing that number until you see a spike in people unsubscribing. That’s the sign you’ve pushed things too far and it’s time to dial back.

That testing strategy has a big downside, though—it literally requires you to suffer through a big wave of unsubscribes. That’s why you may want to create an opt-down option before you begin the tests.

Allowing users to pick their preference on frequency.

An opt-down option is a nice thing to offer your subscribers, and gives them an alternative besides the binary option of subscribed or unsubscribed. With an opt-down option, subscribers can choose their own frequency. You can give subscribers a limited number of choices (say, “all emails” or “weekly roundup/digest”) or, depending on the nature of your email marketing, even more choices (including things like updates, notices, personalized recommendations, and more).

By offering an opt-down you may be able to save a lot of good customers who would otherwise unsubscribe from your list. A study found 40.3 percent of people said an opt-down option would keep them on a list from which they’d otherwise leave. (PDF) And another found nearly three-quarters of people who unsubscribe say they actually rather wouldn’t leave that brand’s email list, they were just getting too many emails and emails that were irrelevant—so an opt-down option or chance to tailor email preferences is perfect for people in those situations.

Once you do figure out a good cadence for your emails, it’s smart to set up an email marketing calendar. That will help you plan ahead for seasonality and holidays, and to make sure your team is coordinated on what is going out when. 


Deliverability is the final piece of the sending formula. It’s a measure of how many of your emails reach your subscribers’ inboxes without bouncing or going to spam. Approximately one in 10 legitimate marketing emails winds up going directly to spam, and overall, about one in five emails never reaches the inbox.

Factors that determine deliverability

There are several factors that mail providers (Google, Microsoft, Yahoo, and others) use to determine the deliverability of your email.

IP address

Does your IP address have a good reputation, or has it been associated with spam or lower-quality content? You need to know what IP address your emails are coming from. Do you have your own dedicated IP, or are you using a shared IP with other companies? If the IP address has a strong reputation, the chances of strong deliverability are higher.

Domain name

Much like the IP address, what domain name (e.g. is your email coming from? Part of your sending reputation is tied to the domain name—if your domain has a clean history and your emails usually wind up in inboxes and not spam, that helps future emails continue doing the same.


Does your content look legitimate or show indications it might be spam? Spam emails are notorious for using mostly images and little text, foreign characters and symbols, broken HTML code, and words like “make money now” and “Bitcoin.” A well-designed email with good content shouldn’t come across as spam.

Here’s a list of common spam trigger words, courtesy of YesWare.

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Mail providers will also scan your emails to look for links to any domains that appear on spam blocklists. If you’re linking to those types of places it can make your emails appear to be spam themselves.

Spam traps

There are two types of spam traps. The first are old emails that users have canceled. Mail providers and anti-spam companies will sometimes take over those addresses and use them to catch spammers—as they might be buying old email lists, harvesting old emails off websites, or even just sending to random email addresses hoping some belong to actual people. The best way to avoid spam traps is good list hygiene—before an email address becomes a spam trap, the emails sent there should bounce for a while. If you’re regularly purging bounces, you’ll be purging addresses that might one day become spam traps.

And mailbox providers and anti-spam companies know those emails are on some legitimate companies’ lists—poorly maintained lists. They’re also on the lookout for that. A well-maintained list is a sign of dedication to quality email marketing, so, therefore, if they see you have a poorly-maintained list, they can interpret that as a lack of dedication to quality email marketing. That hurts your sender reputation.

The other type of spam traps are original email addresses that mail providers will post on the web, knowing spammers will sometimes build their lists by harvesting emails that are published publicly. Unlike the other type of spam trap, there’s no reasonable explanation for having one of these fresh spam trap email addresses on your list—so it’s bad news if you get caught sending to one.

“Unknown users” are a cousin of spam traps. If you send an email to an address that doesn’t exist now and never has before, you’ll get a hard bounce back with an error message like “User unknown” or “Mailbox does not exist.” Those emails need to be removed immediately. (How would they wind up on your list? Someone could mistype their email when they’re subscribing—or put in a fake email address if they’re just trying to quickly get to some walled content.)

Inactive subscribers

There’s a reason why we recommended removing inactive users from your list in our lesson on unsubscribing. When people aren’t opening or clicking on your emails, it’s a signal to mail providers that you’re not sending wanted content. If you have a large number of inactive subscribers, they can certainly hold it against you.

Complaints/spam reports

Complaints are one of the top factors in a poor reputation score and decreased deliverability. The most common way for a subscriber to complain about you is by marking your email as spam. (They can also send a message complaining about you to the email provider or to a filtering or blocklisting application, but those are much less common.) A complaint rate over 0.1 percent, or one out of every 1,000 emails, can have a negative effect on your deliverability. (PDF)

Ways to improve deliverability

The first thing you’ll want to do to improve deliverability is, well, see how you’re currently doing. You can calculate a rough deliverability rate by taking the number of emails you sent, subtracting bounces, and dividing by the total number sent. That won’t take into account how many spam folders you wound up in, but it’ll, at least, give you a starting point.

You can also look at your Sender Score. That’s a metric that takes into account lots of different factors, including complaints, blocklists, and reputation, to determine the likelihood that an email from your IP address will make it to an inbox. IPs with top scores, between 91 and 100, see a delivery rate of 91 percent. Just one level below, between 81 and 90, and that delivery rate drops to 71 percent. A level below that, between 71 and 80, and it’s down to 44 percent. (PDF) So, yes, you’ll want a Sender Score above 90.

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Here are some ways you can improve your deliverability to help your emails reach your subscribers’ inboxes.

Maintain a healthy list

List hygiene is a proactive way to keep your email list healthy. You can’t (really) control when people mark you as spam or go inactive—but you can keep your list as clean as possible to cut down on those numbers.

Remove bounced emails and unknown users immediately (especially if the first email is bounced or returned). Use win-back campaigns to gauge whether dormant subscribers are still interested in engaging with you, and purge them if they are not.

Email your list regularly

If you only send one email every six months, you’re going to have so much turnover in the timeframe that you’ll be facing a huge wave of bounces, inactive subscribers, and spam complaints.

Make it easy to unsubscribe

For legal purposes, there needs to be a clear place to unsubscribe in a marketing email. But if that link isn’t easy to find—like it’s in light gray text or your word choice is something like “Want to leave us?”—people may click the spam button rather than unsubscribing the preferred way. Unsubscribers won’t hurt your Sender Score or deliverability—but spam reports will. 

Don’t wildly increase your volume

It’s a red flag to mail providers if suddenly after months or years of sending one email a month, you start sending two a day. If you are going to increase your volume, ramp up gradually and try to stay consistent. It also helps to ramp up gradually when you’re first starting out and establishing your IP and domain’s reputation.

Stay consistent with your IP

You can’t fix problems with your reputation by switching to another IP address, or by using multiple IP addresses to send from. Spammers use those tricks and the mail providers know about them. Work on rebuilding your reputation by sending good emails that your subscribers will want to open (and, if they notice in their spam folder, will click “this is not spam”).

Don’t get too “clever” with the from field

We discussed different ways you can use the from field in our lesson on inbox presence, but there’s a reason most brands will just go with their company name. If a subscriber doesn’t recognize the name in the from field, it could hurt their chances of opening the email—or, in the worst cases, they could mark it as spam immediately.

It’s good to stay consistent with your from field. If your emails come from “Joe at Shoerama” for a month, then suddenly switch to “Susan at Shoerama” and then to “Ted at Shoerama,” that could cause people to mark your email as spam because they don’t remember who you are.

Send anticipated emails with good content

You want your subscribers to open your emails—that’s a big sign to mail providers that those emails aren’t spam and are wanted. So if you’re sending the right frequency of emails featuring the content your subscribers signed up for and want—and your clean list of subscribers are opening those emails and reading them—those are all excellent for your deliverability.

There are a few other subscriber actions the mail providers look for that help them gauge whether or not you’re spam (and whether or not you’re sending good email). When subscribers add you to their address book, forward your email to friends, reply to your email, file it into a different folder, or click the “this is not spam” button if you do wind up in the spam folder—those are all extra signs of engagement to the mail providers. You can’t really control whether your subscribers take any of those actions, but they’re still good to know—and if there’s a way you can nudge subscribers in the direction of any of them, it could be worthwhile.

Summary and implementations


A critical step of the sending puzzle is making sure your emails are seen by your subscribers—which means the right number of emails arrive at the right days and times, and actually make it into the inbox and not a spam folder.

Email day and time

There’s no universal answer for the right day of the week and time of the day to send your emails—it varies by industry, location, and customer. Some major studies have identified some broad patterns, however, which you can use as a jumping off point.

  • Weekdays are better than weekends, and Friday is the shakiest weekday.
  • Mid-morning is the best time, nights and the middle of the night are the worst time to send.
  • Afternoons are also an alright time to send, but probably not as good as mornings.

You can figure out the best days and times to send for your store by running tests comparing one day or time against another. And when you find the perfect time, you may want to consider segmenting your list so everyone is getting the email at, say, 10 AM in their own home time zone.

Email frequency

There’s also no universal answer for the right email frequency. Your subscribers do want to hear from you (almost two-thirds want to hear from you at least weekly), but figuring out how often, again, depends on a lot of factors. While studies generally find that more, not fewer, emails is better, there are questions you need to ask yourself as you begin to figure out your ideal frequency.

  • How often do you have something worthwhile to send? The biggest determiner of frequency should be the relevance of the emails you’re sending—if everything you send is interesting, helpful, anticipated, and/or wanted, your subscribers won’t have a problem with how often you’re emailing them.
  • How often will your customers receive automations? Don’t forget to add your automations into your frequency calculations. If you decide to send two or three broadcast emails a week and forget your customers are receiving lots of automated emails from you as well, you’re probably overdoing it on frequency.
  • What do you sell and how big is your company? Your frequency can depend a lot on your business fundamentals. Daily deal sites, major retailers with huge catalogs, and personally-driven info products can lean toward daily or almost daily emails. Smaller companies with fewer products, luxury and premium brands, and B2B companies can lean toward less frequent emails.
  • What is your competition doing? Subscribe to your competitors’ email lists and observe how frequently they’re sending. While you don’t want to imitate your competitors, they can provide a good litmus test of what customers in your niche expect in terms of frequency.
  • What expectations did you set? Do you mention a particular email cadence with the signup form on your website (e.g. “Get our weekly newsletter”)? If so, it’s important to stick close to that frequency, as it’s what subscribers internalized when they signed up for your list.

One you’ve figured out a good baseline for your email frequency, you can start testing and gradually increasing your sends per week—until you see a big pushback from your list in the form of lots of unsubscribes. That’s your sign to rein things in. 

You can also offer an opt-down option for your list, where instead of unsubscribing, people can choose to get fewer or more tailored emails from you. It’s a good way to save (a potentially large number of) customers who would otherwise unsubscribe altogether.


Deliverability is a measurement of how many of your emails actually reach subscribers inboxes without bouncing or going to spam. You want to keep the number high, but it’s a challenge—about one in five emails never reach the inbox.

There are lots of factors that the mail providers weigh that go into your deliverability.

  • IP address. Is your IP address clean, with a strong reputation, or has it been associated with spam or other lower-quality content?
  • Domain name. Your domain name is also connected to your reputation—if it has a clean history and emails from that domain usually hit inboxes and receive clicks, that helps future emails continue to do the same.
  • Content. Does your content come off as legit, or are you using techniques spammers use like lots of images and little text, broken code, and spammy words? And are you linking to reputable websites within your email?
  • Spam traps. Mail providers use spam traps to catch people with out-of-date lists or lists of emails they’ve harvested from the internet. You can avoid them by regularly purging inactive subscribers off your list.
  • Inactive subscribers. Send win-back emails to try to re-engage people who’ve stopped interacting with your emails—but if they continue failing to interact, remove them from your list. The mail providers look at open rates as a sign that your emails are wanted, and not spam.
  • Complaints and spam reports. Maybe the biggest factor in mail providers thinking you’re sending spam is… when people tell them you’re sending spam. When someone clicks the “mark as spam” button for one of your emails, your reputation takes a hit—and if it happens enough, it can have a big negative effect on delivery.

Fortunately there are ways you can improve your deliverability. First, gauge how you’re doing by calculating your rough deliverability rate (emails sent minus bounces, divided by emails sent) and get your Sender Score. Then you can take these steps to improve your reputation.

  • Maintain a healthy list. Purge bounces and inactives, use a double opt-in to make sure subscribers really want to be there (and use a real email address), and email your list regularly.
  • Make it easy to unsubscribe. You need to give an unsubscribe option in your email for legal reasons. But if your link isn’t clear or the phrasing you use is confusing, people who would normally unsubscribe might mark you as spam instead.
  • Don’t wildly shift your volume. If you go from sending one email a week to two a day, it’s a red flag to mail providers. Gradually ramp up your frequency.
  • Stay consistent with your IP. You can’t fool the mail providers by switching to a new IP address or sending from multiple IP addresses.
  • Don’t get too clever with the from field. You want people to know who an email is from when they see it in their inbox. If your from field is ambiguous, it could hurt the chances of someone opening an email—and they might even mark it as spam immediately.
  • Send anticipated emails with good content. If your subscribers are opening your emails, that’s a big sign to the mail providers that those emails are wanted. So if you’re sending the right frequency of emails and featuring the content your subscribers signed up to receive—and your clean list of subscribers is opening those emails—that’s a big boost to your deliverability.


Step 1: Figure out your ideal date and time

  • Go through your sending history and observe if emails sent at a particular time or day of the week have performed noticeably well. That can be your jumping off point for testing.
  • In lieu of that, pick one of the “average” top days and times (say Tuesdays at 10 AM) and begin testing that day and time against others.

Step 2: Figure out your ideal frequency

  • Go through the list of questions in this lesson to determine a baseline for a good frequency in your industry or business niche.
  • Slowly ramp up your frequency, carefully monitoring for jumps in unsubscribes.
  • If that number goes above the eCommerce industry average of 0.23 percent (as we discuss in our lesson on analytics), it’s time to scale back your frequency.
  • Put together an email marketing calendar to plan future sends.

Step 3: Improve your deliverability

  • Find your current deliverability by calculating your rate and getting your Sender Score.
  • Make a list hygiene plan (say, cleaning your list once every three months and automatically removing bounces and inactives).
  • If your deliverability score is critically low, take stronger measures like reassessing your content and frequency, or even asking customers to check for your emails in their spam folder and click “this is not spam.”