When should you use Preview text is intentional?
email-preheader · functional · recommended
When should you use this check?
Run this on every campaign where getting opened is the point. The preheader is the line beside your subject in the inbox, and when it is not set the client takes whatever text comes first — usually "View in browser" or an unsubscribe link. It is the most-read copy in the send and the most often left to chance, so it is worth checking on the delivered message rather than trusting the editor's preview field.
When should you not?
Skip it on transactional mail whose preview line is inherently functional and unremarkable, and on operational notices where the subject alone carries everything the recipient needs. It is also not a judgement about whether the preheader is *persuasive*, only whether it is present, intentional and sized to be read. If your ESP composes preview text in a way the delivered message does not reveal, verify with a real send rather than assuming the check can see a field it never receives.
What does it inspect?
The inbox preview snippet must be intentional: no boilerplate ("view in browser", unsubscribe) or leaked merge tokens next to the subject line, required preheader content present within the visible window, and no preview-garbling defects in the source.
What does a failure mean?
A failure means the preview line is missing, is one of the phrases that indicate the client fell back to boilerplate, or is longer than the window that will actually display it. In inbox terms that means the second-most prominent piece of copy in your send is either wasted on a utility link or truncated mid-thought. Because it comes from the top of the message body, a failure usually points at template structure rather than at the campaign copy.
What are the Standard defaults — and why?
Four parameters carry the check. `requiredPreheaderContent` is empty by default, so no particular wording is demanded. `prohibitedPreviewPatterns` holds the phrases that betray a fallback — variants of "view this email in your browser", "trouble viewing", "sent in html only", "online version", plus `unsubscribe` and `lorem ipsum`. `maxPreheaderChars` defaults to `130`, the practical ceiling before clients stop carrying it, and `previewWindowChars` to `90`, the narrower span that is actually read — two numbers because the limit you may write to and the span you should front-load into are different questions.
How does an agent call it?
{
"type": "email",
"validations": [
"email-preheader"
]
}
Who governs the Standard?
Schemafirst.org publishes community-governed standards for digital QA. ArbiterQA is a sponsor and commercial licensee of those standards; citation does not mean Schemafirst operates ArbiterQA.
Author ArbiterQA · Reviewed by ArbiterQA · 2026-08-14