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(Plugin) Dependence of incorrect email display on HTML Email line length
(Plugin) Dependence of incorrect email display on HTML Email line length

In this article, you'll learn about the RFC standard for HTML email line length and how exceeding the limit can affect the email's display.

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Written by Valeriia
Updated over a week ago

An overestimation of the number of characters in a line can lead to rendering problems in email clients. If the code for your HTML email exceeds 998 characters in a single line –some email clients may have trouble parsing it.

"There are two limits that RFC standard places on the number of characters in a line. Each line of characters MUST be no more than 998 characters and SHOULD be no more than 78 characters, excluding the CRLF"

The 998-character limit is due to limitations in many implementations which send, receive, or store Internet Message Format messages that cannot handle more than 998 characters on a line. Please refer for more information here.

How to Identify the Problem?

The most common manifestation of this problem is when code fragments appear in your email, often accompanied by display errors or your email being truncated.

Let's take a look at our example closer:

To create an example of the problems this can cause, we developed our custom block, added it to the email template, and sent it with all the code on one line.

The screenshot below is from Gmail Web.

As you can see, the email displays a code array in Gmail, and the bottom of the email does not appear.

Of course, the problem may not appear the same across all email clients since it also depends on the ESPs that handle the code as it passes from the sending service to the mail client.

How do we resolve the Problem?

Ensure that there is a line break every 998 characters or after each tag in your email. If you preprocess your code before sending, you can set a limit in the sending program or check it manually.

In our case, we have an issue related to our custom block, which doesn't work correctly and sticks the code responsible for the content inside this block.

The screenshot shows that line 33 exceeds 998 characters and lacks spaces.

Additionally, it's possible that your ESP is removing line breaks at the moment of sending the email. If such is the case, collaborate with them directly to find a solution to the problem.

Thank you for taking the time to read our articles. We hope you will find this information helpful.

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