The difference between HTML and plain text emails

HTML emails use HTML and CSS to include formatting, styles, and multimedia elements like images and links, making them visually engaging and interactive. In contrast, plain text emails contain only text without any formatting. 

While HTML emails offers wider creative capabilities, plaintext emails often harness a personal touch that can’t be overlooked. 

HTML emails 

What is it? 

Based on a JAMIA study, “Over recent years the appearance of e-mail messages has changed from a plain text style with unattractive fonts (courier) to more flexible hyper text markup language (HTML) options that can be defined by the sender and adjusted to the characteristics of the recipient.”

An HTML email is a type of email that uses HTML (HyperText Markup Language) to include formatting and multimedia content. Unlike plain text emails, which contain only text, HTML emails can feature a variety of design elements such as different fonts, colors, and layouts, as well as images, links, and even interactive features like buttons. 

The main purpose of HTML emails is to engage recipients through visually appealing and interactive content that enhances the communication of marketing messages, newsletters, or promotional materials. Typically, marketers and organizations create these emails using email marketing software or tools that help to design, send, and track the performance of email campaigns.

How it works 

1. Creating the email: The email designer or marketer writes HTML code, much like coding a webpage. This includes defining the structure with HTML and styling it with CSS. They can add images, format text, and create layouts that make the email attractive and easy to navigate.
2. Sending the email: When the email is sent, this HTML content is included in the body of the email message. The sender uses an email marketing platform or service that supports HTML emails. These platforms also handle the technicalities of email delivery to various types of devices and email clients.
3. Receiving the email: Once the email reaches the recipient's inbox, their email client (like Gmail, Outlook, etc.) reads the HTML code and renders the email similarly to how a web browser would display a webpage. The client interprets the HTML and CSS to present the formatted text, images, and interactive elements.
4. Interaction and compatibility: Recipients can interact with the email—clicking on links, viewing images, or following calls to action. Email clients differ in how they interpret HTML and CSS, so the email must be tested on multiple clients to ensure it looks good and functions well everywhere it might be opened.
5. Tracking and analytics: Embedded within the HTML email can be invisible tracking pixels or linked elements that report back when a recipient opens the email or clicks on a link. This data helps senders understand the effectiveness of their emails and refine future campaigns.

Plain text emails 

What is it?

A plain text email is an email that contains only text without any formatting or multimedia elements like images or links. Its primary purpose is to deliver messages in a simple, straightforward format that can be read on any device and by any email client, ensuring maximum compatibility and accessibility. Typically, plain text emails are composed directly in an email client or through email marketing platforms that support simple text-only messages. 

How it works 

1. Composition: The email is composed using only characters available on a standard keyboard, without the use of HTML or CSS for styling. This ensures that the email consists strictly of text.
2. Sending: When you send the email, it travels from your email server to the recipient’s email server through Simple Mail Transfer Protocol (SMTP). Since the email contains only text, it's lightweight and generally transmits quickly and efficiently.
3. Receiving: Once the email reaches the recipient's server, it is stored until the recipient opens it with their email client (such as Microsoft Outlook, Gmail, or another email service). Plain text emails are universally compatible with all email clients.
4. Display: Upon opening the email, the recipient sees a message that displays exactly as it was typed, with no special formatting, fonts, or embedded images. The simplicity of plain text emails ensures that they look the same on all devices and email clients.
5. Interaction: Recipients can easily respond or forward the message. However, any links included in the text must be copied and pasted into a web browser, as plain text does not support clickable links.

How to choose the right format

1. Understand your audience: Knowing the preferences and the technical capabilities of your audience is required. If your audience primarily accesses emails via mobile devices or older email clients, plain text may be more effective.
2. Consider the purpose of the email: If the email is intended to convey straightforward, information without the need for visual engagement, plain text might be preferable. However, if the email's purpose is HIPAA compliant email marketing or branding, where visual impact is necessary, HTML might be the better choice.
3. Analyze past engagement data: Look at how previous emails have performed in terms of open rates and click-through rates. For instance, in surveys performed by Hubspot:

• A plain-text email versus an email with a .GIF image showed that the .GIF version had a 2.3% lower clickthrough rate, and combined with the open rate, the plain-text version received 42% more clicks.
• When comparing a plain-text email to an HTML email with images, the HTML version had a 21% lower clickthrough rate, and along with the open rate differences, resulted in 51% fewer clicks.

1. Test and optimize: Continuously test different formats to see which performs better with your specific audience. This includes A/B testing various elements like the use of images, different types of content layout, and even the inclusion of interactive elements in HTML emails.
2. Evaluate email content compatibility: HTML emails allow for creative designs and interactive elements, which can enhance engagement if your audience appreciates visual and interactive content. However, if the compatibility and simplicity of plain text better serve your message delivery, it should be used instead.
3. Consider deliverability and spam filters: HTML emails are more likely to be flagged by spam filters than plain text emails, particularly if not properly optimized. If deliverability is a concern, plain text may be a safer choice.

See also: Top 7 HIPAA compliant email marketing services

FAQs

Are plain text emails more secure than HTML emails?

Plain text emails are generally considered more secure because they lack the HTML code that could potentially harbor harmful scripts. However, both types can contain malicious links.

Do all email clients support HTML?

While most modern email clients support HTML, there are exceptions, especially among older or less common email software, where rendering issues may occur.

Can I switch from HTML to plain text after starting an email campaign?

Yes, you can switch formats, but it's needed to consider how this change might affect subscriber engagement and the consistency of your campaign’s appearance and functionality.

How does the choice of email format impact email deliverability?

HTML emails are more prone to be filtered by spam filters if not properly designed, whereas plain text emails generally have fewer issues with spam filters and deliverability.