7 Email Marketing Mistakes to Avoid

When email is just a fraction of your marketing strategy and you have a million other priorities, it’s easy to let a few important things slip. We’ve put together this list of common missteps that you can use as a checklist when sending campaigns or thinking about your email strategy holistically.

1. Using your main domain to send all emails


Subdomains are key in building a strong, stable sending reputation, but it’s common for brands to default to sending all email from their main domain.

Each individual subdomain you use gives you a separate reputation (which is also separate from your parent domain). Separating out your reputations is especially important for brands sending lots of email, which often gets split into transactional (think: order receipts, shipping notifications, password resets) and marketing emails (promotions, new releases, etc.).

It’s pretty typical for transactional emails to get much higher engagement, because they’re emails people need to receive (just think about how quickly you opened your last password reset email). On the other hand, it’s likely your marketing emails will have less engagement - not necessarily poor engagement, especially if you’re using personalization and segmentation - but on average they will have less.

Separating these out lets you keep your reputations separate, and ensures that all necessary transactional emails will make it to the inbox.

If you want to learn more about why we recommend subdomains, you can check out this post for an in-depth explanation: Why You Should Be Using a Subdomain.

2. Not warming up your IP

This comes to the forefront when you’re using a new subdomain or switching email providers. It’s tempting to just continue business as usual, sending the same email volume as you did before the switch, but the best plan of action is to slowly scale up your sending in order to warm up your IP.

This will prevent your emails from being flagged as spam. When ISPs (Gmail, Outlook, etc.) suddenly see a new IP sending high volume email, they often assume it’s coming from a spammer (setting up new domains and sending mass emails is a spammer’s M.O.).

By slowly scaling up your normal sending volume by starting with smaller segments in the preceding days or weeks, you can avoid getting flagged and preserve your sending reputation in the long run.

3. Forgetting to segment

If your subscribers range from 21-year-old males in New York to 34 year-old females in California, sending the same email campaigns to your entire list isn’t the most effective strategy.

There are a few ways to segment subscribers and send more targeted campaigns that are worth it for the increased ROI.


This includes all the baseline, general data about your audience, like age, gender, occupation, salary, etc. Segmenting by simple attributes like gender alone is an easy way to increase relevance and clicks.


You can use location data to send emails based on time zones, ensuring that you’re hitting customers’ inboxes at the optimal time whether they live on the east or west coast.

If you have seasonally relevant products, location can also come into play to separate out customers who will find certain items irrelevant - for example, you probably don’t want to send an update about new winter jacket arrivals to Californians.


Using actions to automate emails at significant points in a customer’s journey is one of the best ways to increase campaign engagement and conversion. The options for triggering on customer actions are endless - from when they sign up for your list, abandon a cart, or make their first purchase. It really can’t get more relevant than sending emails based on how a customer is interacting with your brand.

This post dives deep into segmentation: Perfecting Your Ecommerce Email Journey through Segmentation.

Casper has mastered sending email based on customer actions. Here’s an example of one of their abandoned cart emails:


4. Bad subject lines

The best subject lines are specific, incite action, and give a good overview of what’s inside your email. By flipping your subject line from “Sale on Now!” to “50% Off Summer Blowout, Today Only!”, you’ll give your customers much more incentive to open your email and take action.

For tips on crafting better subject lines, take a look at this post: Want to increase your email opens? Try these 8 subject line formulas.

EyeBuyDirect are subject line (and pun) experts:


5. Sending email inconsistently

Just like how warming up your IP is important for deliverability, it’s also a good idea to have an email strategy that includes consistent email sends. This will continue to differentiate you from spammers who send large, sporadic blasts, letting ISPs know that you’re sending legitimate emails that your customers want to receive, and giving you great inbox placement in the long run.

6. Too many calls-to-action (CTAs)

It’s tempting to jam-pack your email with everything you can think to include, but in order to guide your customers towards your desired outcome your emails should push users towards one specific action. By focusing on one clear goal and tying it to your most prominent CTA from the get-go, you can make sure you’re focused on what’s most important.

This blog post includes helpful tips on crafting your email templates around your CTA so you can maximize conversion: Tips for Crafting Email CTAs that Drive Clicks.

Dollar Shave Club’s clear CTA is sure to drive action:


7. Not testing for mobile

Over 50% of emails are opened on mobile devices, so testing your templates for mobile screen size is imperative.

Things to check:

  • Layout. Look to see that your layout translates well from desktop to mobile, especially if you’re using a multi-column layout. Tip: If you’re having desktop to mobile layout issues, a quick fix is to make your template one column.
  • Font. Font size and type can appear differently on mobile than on desktop. Check your font and heading types on desktop if you’re seeing a disparity between the two.
  • Loading times. If your email is loading slowly on mobile, try compressing your images with a tool like TinyPNG.

TOMS’ one-column email displays beautifully on desktop and mobile:


Check your email strategy

This post has covered everything, from common missteps that hurt email deliverability, to ways you can think about formatting to optimize your emails. To make an impact on your current strategy, try checking it against some of these tips to see how you measure up. By remedying one or two mistakes, you can have a huge impact on your campaigns right away!