Email Content Best Practices

Published on 2020-05-16· Updated on 2021-12-15

The way you write the content of your email and the way you structure it can make a huge impact on email delivery and open rates in email marketing. This guide will give you a list of email content best practices to follow while generating an email message for a bulk email campaign. Why do you need to follow Email Content Best Practices? well, let's look at this scenario.

You are noticing that your emails are more often considered as spam, even after various efforts from your side. Having confirmed a good domain reputation, are not listed into the multiple blacklists, consistent email volume. Everything looks great, where is the problem?

Well, have you checked the emails you are sending in detail? Email content analysis might reveal much about the problem with your content. This article covers some best practices you can follow to land your email in the inbox and prevent being tagged as spam.


Email Subject Line

A Subject Line is one of the essential parts of the email, and this is the first thing a user reads at first glance. That's why you need to put a lot of thought into how you would want to write it. Here are some tips for you.

  • Try to use personalized title addressing the recipient's name, location, exclusive deals on a birthday. 
  • Be direct with what you want to say. The title should send the content that users will be finding inside the email body.
  • Being descriptive doesn't mean you should make it too long. Try to keep it under nine words. More than that might get clipped in the mobile view.
  • Don't fill it up with too much emojis.
  • The email subject line should accurately represent the content of the email body.
  • Avoid using Full caps words "HELLO THERE."

Email Content

Email content should be engaging with images and text and hyperlinks connecting to the related site you want users to land.

The customized content like mentioning the recipient name or location in the email makes it more personal and engaging communication rather than just an email that can be addressed to anyone. Better opening rates can be achieved if you give the person personalized offers. For instance "It's your birthday so 15% off for you".


You should have engaging and original text content. Don't just copy-paste anyone's content in your email. This will more often will make you less susceptible to problems that involve the content in that email and would also look authentic as it will be catered for your audience only.

Your email content should have multiple versions and should vary from individual to individual.

Start your email with the right words to make the user know what you are providing in the email. The inbox providers now days are using email preview in their emails. This preview takes the beginning part of the email body by default.  

If you don't want to do this, or can't do this, then you can also customize your email preview text. This will make it a lot easier for you to make the people open and read your emails.

Content Relevance

Content relevance for the recipient. For this, you should research a bit about what users are you targeting. And try sending emails to opt-in lists only.

Also, most of the email marketers should use targeted emails to be relevant to the type of person they are sending the emails.

Content relevance also helps when your emails are regularly being not opened by the email recipients.

Avoid Spammy content

The email content you send to the recipients defines what are the intentions of your email is. Let it be less of forced product placement and more consistent and elaborating with the email subject. Here are some guidelines for spam content in the email.

  • Avoid words that are considered as spam by spam engines to avoid being flagged. These words include.
    You've Won
    Order Now
    Exclusive deal
    You Have Been Selected
    Act Now
    Buy Now
    And there are many more. You can check them here.
  • Again as mentioned in the Subject line, do not use ALL CAPS letters.
  • Don't use multiple exclamation signs in the email as it sounds being a promotion or a forceful marketing message. For example, "Hey, check this out!!!"

Email Structure


If you are sending HTML content in the email, which you are since you are marketing through emails, then there are some things that you should avoid. The more lightweight and jumbled the HTML structure is, the better your visibility and processing will be when sending your email for inbox. Just make sure you follow these listed pointers:

  • Avoid a really large size complex HTML code. The more complex the code it, the more problem it will have to be rendered into the email message.
  • Try not adding too much CSS. Again to make it less complex and lightweight.
  • Try adding all of the CSS styling inline.
  • Remove all of the scripts from your HTML code. Most of the email clients commonly won't allow js into the content. It
  • The email you are sending should be straightforward in structure. Keep it limited with some images, text, and hyperlinks.
  • Remove the HTML code that you don't need in your email body structure. Remove the email element attributes that are not important for the email, such as the alt attribute for the image tag.
  • Keep the HTML to bare minimum and more readable by the inboxing services.
  • If you are sending multipart messages, use base64 encoding to encode the body or attached files.

Email size

When you are sending bulk emails, you want the email delivery to be fast and with less processing as possible. Even though you can send emails in MBs (MegaBytes) and there is no limitation of the length of emails you can send, It is recommended to keep it small.

You have to keep in mind the email size while creating a marketing email. Email marketers can go too creative while making an email fit for their campaign. And while adding as much content in the email as possible to make their campaign great, they forget to keep the email size in check.

We recommended keeping the email size under 150kb to make it less susceptible to the email spam filters.

SMTP messages for email size

(Error Code)523 - Check the size of the email body; the SMTP server cannot accept or process the size of your email body.

(Error Code)552 - Storage size of the recipient's inbox is full and cannot save this message. The recipients need to clean their email inbox to deal with this.

Links in the email are a great way to make the user land on your landing page, but there are ways of doing it wrong. Following are recommendations for putting links in the email.

  • Add the link for the landing page of your website in a button. Doing this will make more people click on it since people are more likely to click buttons than links.
  • Try to add less number of links in your email. Too many hyperlinks are of no use and frankly is suspicious. It also makes your email HTML more significantly getting moved to spam.
  • Make sure that the links that you are adding points to your domain. A link to the external domain is suspicious.
  • Use full links instead of short links in the links.
  • Do not add any of the hidden links in your email body content that is not seen in the HTML rendered message. It looks suspicious.


Images are the best way to make engaging emails. Pictures make the recipient more interested in email. There are certain things that you should be careful while adding images into the email body.

Images should be not a large image and should not be in MBs.

The source of the image you are putting in the email should be hosted on your server. If it is hosted from some domain other than your sending domain, then it will create a problem.


In the case of inboxing services such as Google, the attachments always need additional processing due to virus scans. Also, if your attachment is somehow considered harmful by Google, then you might be regarded as a spammer.

Try to provide most of the things to the user using the email images and text. For instance, there is a form you want the recipient to download, instead of attaching it to the email, add a link to the document which is again, hosted on your domain.

Send Test Emails to Yourself

This point is mentioned last but is one of the most crucial steps to be taken. No matter how much work you put into creating the best email you can, you cannot be sure without testing.

By sending an email to yourself, you can test all of the above steps in a practical scenario.

You will see that most of the changes you made might look good on the paper, but practically it doesn't work right.

Delivery Testing and Incremental Changes

While you are sending emails and testing all of the email components one by one, you will be making incremental changes to the message until you get it just right. You can tweak content and make incremental changes.

After a rigorous amount of testing, you put in the email creation; you can be sure you will have no problems in sending the emails.

The delivery part of the emails should be checked after each email delivery one by one.

In order to make your email better, you should be answering these questions.

Where is the email landing in the inbox?

Is it more prone to be considered spam?

Do we want this to land on the promotions or inbox? 

Based on these questions you can tweak your content to match exactly how you envision your email being delivered in the recipient's inbox.


These are some of the little things that will add up to make it easier to generate emails with a good score and will prevent you from being added to the spam.

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Hitesh Pandey💻

Full Stack Developer, Pepipost

🥑 Developer Evangelist | 🥇Email Geek

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