Limitations of HTML email

Most email clients don’t support every type of HTML content that is shown on the web. This means that scripts, animations, and complicated navigation that work perfectly for web browsers won’t work for most email inboxes. 

To make an HTML email look nice, avoid the following types of content in your email campaigns and find out how to replace them. 

Do not use

<Style> tags

Having <style> tags in your HTML email source code may cause issues while rendering email’s final look in the recipients’ inbox since most email providers will likely cut them off.


JavaScript is a programming language that allows you to create interactive content. Although it’s wide-spread across the web, almost all email clients automatically block it since such content might be harmful. 


An inline frame <iframe> is an HTML element that embeds content from one website into another. IFrames are usually used to insert ads, video, audio, or forms in other websites. They often contain a JavaScript code, so most email clients disable them. 

Instead, add a link to the content you want to show in your email.

Embedded media

Generally, most email clients don’t support videos and audios by default. Just a few of them, including Apple Mail, currently support HTML5 <video> and <audio> tags for embedded media. Unless the majority of your audience is using Apple Mail, embedding media in your email drip campaigns is not the best idea.

Alternatively, you may add a text link or place a button over an image to encourage your recipients to click the link for a video or audio. Besides, you can also use an animated GIF.


Flash is usually reserved for animations and graphics on websites, and it won’t work in an email inbox as it can be suspicious. It’s blocked by most email clients since it can allow hackers to take control of your computer because it’s insecure.

Again, we suggest adding GIFs instead to make your content more interesting. Or, if you want to show recipients something using Flash, it’s better to add a link to your email leading to the needed content.


This is a tricky one. Although most email clients support form elements with simple HTML such as text fields, text inputs, radio buttons, and checkboxes, the submit button can often be problematic as it requires JavaScript. You should avoid JavaScript in HTML emails, remember? 

Try adding a link to the web form instead. 

Be cautious

It’s not over yet! You’ve just read the list of content you should avoid in your email drip campaign. And here’s a list of content you should be cautious about while using. 

Please review and test your email drip campaigns before sending them to the whole audience, because not every email client supports the following elements:

Web fonts

Be careful here as well because not every email client supports custom fonts. To correctly display fonts on emails, recipients must have them installed on their computer. Thus, the solution here is to add an alternative font that can be found on every computer. 

It’s recommended that you use only web-safe fonts in emails such as Times New Roman, Verdana, and Georgia as they have the highest compatibility.

Background images

Some email clients, specifically Outlook (2007+) and Hotmail, may block images in your email campaigns, while others just don’t support them. Besides, the background image can render differently depending on the device. Thus, we recommend testing the email beforehand to handle all the possible issues.

Wide templates

Your subscribers often open campaigns on mobile devices or in the preview pane of desktop email clients. Email viewing panes are narrow, so they’ll cut off your message if it’s wider than 600-800px. Make sure your email is of a maximum width of 600px.

Now that you know the limitations of HTML email design, use them to your advantage. Be careful with your content and double-check your HTML email before spreading it to the world.

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