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Internet Message Format

A fundamental pillar in the world of email marketing

Internet Message Format is a standard that defines the exact structure and format of email messages sent over the Internet.

Established by the IETF (Internet Engineering Task Force), this format guarantees interoperability between different email systems.

It allows messages created using text, images and other types of content to be sent and received efficiently and without interpretation errors.

Relevant historical data

The history of the Internet Message Format goes back to the early days of the Internet, when it was still known as ARPANET

At that time, the need for a standardized format for exchanging messages was evident.

As the Internet evolved, the complexity of the messages sent also increased, which led to the creation of more robust standards.

RFC 822, published in 1982, established the basis for formatting messages on the Internet and was later updated by RFC 2822 in 2001.

It was subsequently updated by RFC 5322 in 2008, reflecting the changing needs and increasing complexity of digital communication.

Key considerations

The Internet Message Format covers technical specifications that include, among others, the following:

  • The syntax of message headers
  • Character encoding
  • And date and time formats

These elements are essential to ensure that the content of the message is faithfully preserved during transmission.

And that it can be interpreted correctly by the recipient’s email software.

In addition, the format supports the inclusion of metadata in message headers, which enables a wide range of functionalities, such as message classification, spam filters and authentication techniques.

Why it is important, advantages

In the context of email marketing, the Internet Message Format plays an essential role.

Firstly, it ensures that emails sent as part of marketing campaigns are compatible with a wide range of email clients.

From desktop applications to mobile platforms.

This is key to effectively reaching a diverse audience without technical concerns limiting the delivery or presentation of the message.

Secondly, the standardization of the format allows marketers to use advanced personalization and segmentation techniques.

By understanding and using the headers and structures defined in the Internet Message Format, marketers can create messages that grab the recipient’s attention.

And that also provide a consistent and engaging user experience.

Thirdly, effective use of the Internet Message Format helps to improve email delivery rates.

By adhering to best practices and standards, email messages are less likely to be flagged as spam.

This ensures that email marketing campaigns reach recipients’ inboxes, where they have more chance of being seen and read.


The Internet Message Format is more than a set of technical rules for structuring emails.

It is an essential component for effective email communication strategies.