What is a pre-header text?
It's an extension to your subject line. They complement each other with the goal of getting your email opened. More about subject lines here.
You can add pre-header content in the message editor.
It's about open rates
Besides the sender name (the "from name") and the subject line the pre-header text is the third key piece of information that influences open rates.
When people receive emails they want to know "Why should I open this email?"
The subject line and the pre-header text should answer this question.
Where is the pre-header shown?
The pre-header shows up in inboxes next to or below the subject line. It's not part of the email and it does not show up in the message once it's opened. Just like the subject line.
Is it mandatory to use pre-header text?
Unlike the subject line, pre-header text isn't required to send emails - but it's highly recommended.
Without a pre-header sentence the first piece of text from your email is displayed in inboxes after the subject line. This is often some non-interesting text, such as a “view online” link, a date or salutation. This is not a great way to tease your readers to open and read your message.
See the example below of an email in an inbox with and without a pre-header text:
Example of an email in an inbox without pre-header content
Example of an email in an inbox using preheader text:
