When should you use Plain-text version included?
email-plaintext-alt-present · functional · required
When should you use this check?
Run this on any bulk or commercial send, and especially after changing how mail is generated. A missing text part is a classic platform-level defect: it is invisible in every preview, costs nothing to fix, and is one of the cheap signals spam filters weigh against you. Because it reads the delivered message structure, one audited send tells you whether the whole sending path is producing a proper multipart message or not.
When should you not?
Skip it where a text alternative is genuinely irrelevant to the audit — internal notifications to a known client, machine-to-machine mail nobody reads in a mail client. It is also not a judgement of the text part's *quality*: a message carrying an empty or auto-stripped text version passes the structural question while still being useless to a human reading it. If the concern is that your text part is a garbled dump of the HTML, that needs a read rather than a check.
What does it inspect?
Parse MIME structure. Fail when not multipart/alternative or text/plain part is absent/empty.
What does a failure mean?
A failure means the message went out as HTML only, with no plain-text alternative. Some providers treat that as a mild spam signal, so the cost is paid in reputation across your sending rather than in this one campaign, and it accumulates. It also leaves the message unreadable to anyone using a text-only client or a screen reader configured to prefer the text part, which is a small audience with a total failure rather than a large one with an inconvenience.
What are the Standard defaults — and why?
This check has no tunable thresholds. It is a structural presence check on the delivered message: the plain-text alternative is either part of the message or it is not, and there is no number or list to calibrate. Nothing about the answer varies by brand or campaign, which is why the check is entirely zero-configuration.
How does an agent call it?
{
"type": "email",
"validations": [
"email-plaintext-alt-present"
]
}
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