How often should you be emailing customers?

How often should I email customers? How many marketing emails should I send a week? How many in a day? These are these are common questions from marketers regarding email frequency. The simple answer: It depends and there is no one-size-fits-all solution. Like most things, there has to be a balance. Too many emails can result in a high unsubscribe rate. Too few emails can result in your customers not remembering your brand. 

We’ll help you determine the right frequency to email your customers, based on ReSci’s research performed on various brands we have worked with.


Consider your business type and product offerings

Is your website used for eCommerce or informational purposes? If your website is content-only, you still have the opportunity to communicate with your customers on a regular basis. For example you can provide:

  • Ongoing educational series (how to, blog posts, recipes, etc…)
  • Coupons to drive in-store traffic
  • Recipes


Product based businesses – How many product SKUs do you have?

Based on the number of product SKUs you have, you could follow some of the recommendations below. If you only sell a few products, your program may not warrant sending emails every day. You might want to consider only sending 1-2x per week. 


Examine your email marketing metrics

Having a good handle on your email marketing metrics is the key to find the perfect balance in email frequency. You want to look at your engagement metrics, since email frequency has a direct correlation to this. If you’re sending relevant content that your customers are engaging with, then you can possibly be more aggressive with your sending frequency. If you begin to see a decline in your engagement metrics, then you would potentially want to reduce your frequency. 

As a marketer, you should always have a few KPIs top of mind. Here are a few that will help you determine your sending frequency. 

  • Total List Size
  • Active/Engaged Customers
  • Dormant Customers

The total list size is just that. How many customers are opted into your program. 

Active/Engaged are cusomters that have taken action with your email program within a specified period of time (typically within 4-6 months)

Dormant customers typically have not engaged with your program in over 12 months. At this point, it’s probably time to write them off. Sending to these customers will only do harm to your domain/IP reputation. 

Also, customers that aren’t necessarily active, but are not dormant either should be added to some type of a nurturing or winback program that will hopefully get them back and engage with your brand again. 


Advanced: Engagement metrics by ISPs

Here’s where things can get a bit more complicated. You should be able to monitor your engagement metrics across the different ISPs. If you notice that Gmail and Apple for example have great open rates, then you can continue to send to these customers more frequently. If Yahoo & Microsoft have lower engagement rates, then maybe reduce the frequency at these domains. 

Below is a sample frequency policy by domain. This example assumes that there’s an issue with Microsoft domains. In addition to looking at the last open date by each domain, you’d also want to create Low Frequency, Medium Frequency, and High Frequency buckets per domain. 


In this example, we assume Microsoft has an issue. Here’s how we’d recommend setting up our email frequency to Microsoft customers:

  • Low Frequency (send to these customers 1x per week): Last Open Date was within ~ 210 days. These customers aren’t too engaged with your brand, so let’s not inundate them with too many emails. If they’re not opening up your emails, this could cause a decline in overall email deliverability. 
  • Medium Frequency (send to these customers 2-3x per week): Last Open Date was within 150 days. 
  • High Frequency (these customers are active & engaging with your brand. They want to hear from you. You can send 4-5x per week): Last Open Date was within 45-60 days. 


Why you should not email unengaged customers too frequently

There are consequences to emailing unengaged customers too frequently, since ISPs are getting smarter and smarter. If you look at the example below, you’ll see that Banana Republic sends emails on a daily basis. If your customers are not engaging with your email program, then the ISPs will begin to direct your messages to the Spam folder. The more that this occurs, the less your customers will see your messages and your total unique open count will drop. 


If your customers keep deleting your messages, the ISPs will take notice and:

  • More frequent emailing could result in lower email engagement
  • As your open & click rates decline, ISPs notice
  • With continued reduction in engagement, ISPs will think you’re not sending relevant content and will begin to place your emails in the spam folder. 
  • The more your messages end up in the spam folder, the lower your engagement rates will go. 
  • Domain remediation will be necessary to build back your reputation. 


Let’s recap

As mentioned above, there’s no one-size-fits-all template when it comes to email sending frequency. You’ll want to understand the following metrics that will assist you in making your decision:

  • Do you sell products or just provide content?
  • How many SKUs do you have on your website?
  •  Do you understand your engagement metrics?
    • Open Rates
    • Click Rates
    • Unsubscribe Rate
    • Total List Size
    • Engaged List
    • Dormant List


Based on these metrics, you should be able to come up with the best plan for your business, and continue to tweak it as you learn more and more about your customer behavior. Happy sending!


Brought to you by Eric Chebi, who leads our Enterprise Client Success team at ReSci

Eric has over 20 years of experience in the email marketing/marketing technology space and has worked with some of the world’s largest brands including P&G, Zappos, US Airways, Fandango, and Mazda.


Feel confused or lost? Want more strategies? Contact the help desk, or reach out to your Client Success Manager and they’ll be happy to help!


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ReSci is a team of marketers and data scientists on a mission to democratize AI. We make powerful recommendations and predictions accessible to brands. Find out how we can help you connect with your customers.