Learn the Difference Between the Email Body and Its Header

The email body is the main part of an email message. It contains the message’s text, images and other data (such as attachments). The email’s body is opposed to its header, which contains control information and data about the message (such as its sender, the recipient and the path an email took to reach its destination).

How Do the Message Body and Header Differ in Email Programs

Email clients will usually separate the email headers and body.

While only select parts of the header (the most crucial information such as the sender, subject and date) are shown, usually in condensed form, the message body is usually displayed much more completely. (Messages can contain multiple versions of the same text—with formatting and without, for instance—, in which case most email programs will show only one variant.)

When writing an email, the header information (To:, Cc: and Bcc: recipients as well as the Subject and message priority, for instance) will be separate from the message body as well. The body is usually a free-form field that lets you compose without restriction.

Are Attachments Part of the Email Body?

Files attached to a message are technically part of the email body. Often, they will be displayed separately, though, with the common exception of images, which may appear in line with the text.

Is There a Maximum Email Body Size?

The internet email standard does not limit the size of an email’s body text.

Mail servers do have limits on how big a message they will accept, though. Common maximum sizes for email bodies—including attachments—are 10–25 MB.

(The minimum size that must be allowed for an email’s body and header lines combined is 64 KB.)

How Does the SMTP Email Standard Define an Email’s Body?

In the SMTP email standard, the body is defined as the full email message.

That includes both what is commonly called the header (sender, subject, date, Received: lines, etc.) and the email body.

For the standard, the email header is only the information need for the server to deliver the message, essentially the sender and recipient.