An MMS campaign must attach at least one sample media file

The requirementstatement

A campaign that requests MMS capability must supply at least one sample media file alongside the sample message text.

Severityseverity: BlockingBLOCKINGBreaking this rule gets the submission rejected. There is no partial credit.
When it bitesphase: Gates approvalapprovalGet this wrong and the brand or campaign is refused at registration.
What is checkedobject: campaign.mms_sample_media
Where it liveslayer: Message contentMESSAGE_CONTENT
How Ekas settles itdetectability: DeterministicDETERMINISTIC; Settled in code from the values you submitted. No model involved, no judgement call, same answer every time.
What the fix involvesfailureClass: Fix the fieldRETRY_FIELD; A better value in the form fixes it. Ekas can rewrite it and re-check.
Who requires itauthorities: AWS
When it appliesapplicabilityText: Applies when `mmsEnabled` is true.

Why this rule existsrationale

MMS is approved on what the recipient will actually see, and for a picture message that is the picture — a reviewer who is shown only the caption has no way to tell a product photo from something that would fail SHAFT screening on sight. Businesses miss this because the sample text field accepts their submission happily and nothing on the form says the attachment is a separate requirement, so the rejection arrives for a field they never noticed was empty.

How to fix itremediation

Attach the actual image or video you will send to the campaign's MMS sample media, one file per sample message that carries media. Done when every MMS sample has a file next to its text, not just a caption describing one.

A compliant exampleexample

mms_sample_media: acme-summer-sale.png (image/png, 214 KB) — the same artwork the weekend promotion will send.

Common mistakespitfalls

Turning MMS on and leaving the attachments for later is the usual cause: the capability flag and the sample media are separate fields, and the flag is what puts you under this requirement.

Provider rejection codescodes

The code you get back when this rule is what failed, and whether that provider lets you resubmit.

Provider	Code	Resubmit
AWS	MISSING_CONDITIONAL_FIELD	Yes

Rules you will hit next

2 other rules read campaign.mms_sample_media. Fixing one field to satisfy a single rule is how a resubmission trades one rejection for another, so read these before you change anything.

MSG-019Each MMS sample file must sit under its per-type size ceilingBlockingBLOCKING MSG-020MMS sample images must not be placeholder or stock artworkHighHIGH MSG-008Opt-in confirmation must be 20–255 charactersBlockingBLOCKING MSG-009HELP reply must be 20–255 charactersBlockingBLOCKING MSG-011Opt-out confirmation must be 20–255 charactersBlockingBLOCKING MSG-031Sample messages must be in EnglishBlockingBLOCKING

All message content rules

MSG-018 is one of 122 message content rules in the 915-rule 10DLC registry. Free to cite under CC BY 4.0.