{"id":81863,"date":"2024-09-16T20:05:59","date_gmt":"2024-09-16T20:05:59","guid":{"rendered":"https:\/\/mailrelay.com\/glossary\/headers\/"},"modified":"2026-09-28T15:03:06","modified_gmt":"2026-09-28T15:03:06","slug":"headers","status":"publish","type":"glossary","link":"https:\/\/mailrelay.com\/en\/glossary\/headers\/","title":{"rendered":"Headers"},"content":{"rendered":"

Email headers are lines of code<\/strong> at the top of the message that provide essential information about the email. <\/p>\n

They include, among others, the sender, the recipient, the date and time the message was sent, and the subject line. <\/p>\n

However, they go beyond these basic elements and also include technical fields such as \u2018Reply-To\u2019, \u2018Content-Type\u2019 and \u2018List-Unsubscribe<\/a>\u2019, among others. <\/p>\n

These headers are essential for email systems and servers to correctly identify and process messages.<\/p>\n

Relevant historical data<\/h2>\n

The origin of email headers goes back to the early days of email, in the 1970s, when the foundations of digital communication were laid. <\/strong> <\/p>\n

Over time, as email evolved from an academic and military communication medium to a universal tool, the structure and functionality of headers expanded. <\/p>\n

Standards such as the Simple Mail Transfer Protocol (SMTP)<\/strong> and the Internet Message Format<\/strong> played key roles in defining how headers are structured and used for efficient and secure communication.<\/p>\n

Key considerations<\/h2>\n

When designing and sending emails, it is vital to carefully consider headers. <\/p>\n

(Although for the more technical ones, the email marketing tool<\/a> will take care of this transparently)<\/em><\/p>\n

A well-written \u2018Subject\u2019<\/a> header can determine whether an email is opened or ignored. <\/p>\n

The \u2018From\u2019 header must clearly identify the sender<\/strong>, building trust and recognition. <\/p>\n

In addition, technical headers, although not visible, must be configured correctly to avoid spam filters and ensure deliverability. <\/p>\n

Implementing the \u2018List-Unsubscribe\u2019 header is especially relevant in email marketing, as it gives recipients a direct way to unsubscribe.<\/p>\n

Why it is important, advantages<\/h2>\n

Email headers are more than mere technical components. <\/p>\n

They are basic tools in email marketing<\/a>. <\/p>\n

Configuring and using headers correctly can lead to a better delivery rate<\/strong>, higher open and click rates, and a better perception of the sender by the recipient. <\/p>\n

This translates into more effective email campaigns, with a direct impact on marketing results.<\/p>\n

In addition, headers play a crucial role in email authentication and the fight against phishing and spam. <\/p>\n

Implementing headers such as \u2018SPF<\/a>\u2019, \u2018DKIM<\/a>\u2019 and \u2018DMARC<\/a>\u2019 helps verify the sender’s identity, building trust with email service providers.<\/p>\n

Conclusion<\/h2>\n

Email headers are fundamental components of the email marketing infrastructure, essential for both technical functionality and marketing strategy. <\/p>\n

Their proper implementation ensures not only that messages reach their destination but also that they are positively received by recipients. <\/p>\n

In a world where the inbox is constantly cluttered, headers offer an opportunity to stand out, build trust and foster effective communication.<\/p>\n

Related entries<\/h2>\n