Five-minute first-success test

Test the mail merge on a copied Sheet before sending.

This test proves the safety path without touching a live recipient list. Use two rows and inboxes you control, deliberately create one duplicate outgoing payload, then verify the blocker, exact preview, approval, send state, and trigger health.

Do not use customer or prospect addresses for this test. FormMerge is for small operational messages, not cold email, newsletters, CRM, or marketing automation. Gmail and Apps Script quotas still apply.

Install FormMerge Pro Read the duplicate-safety details

Copied-sheet checklist

1. Work only in a copyCreate a copy of the Sheet and keep the first test to two pending rows using inboxes you control. 2. Confirm the duplicate blockerGive both rows the same resolved recipient, subject, body, CC, and BCC. Preflight should block the exact duplicate payload instead of allowing approval. 3. Fix one row and inspect the exact previewChange the second message, rerun Preflight, and read every pending recipient, subject, and body. Do not approve if the output differs from what you intend to send. 4. Approve the unchanged preview and send onceApprove only after inspection. If a row becomes SEND_UNCERTAIN:, check the controlled inbox before retrying; do not send blindly. 5. Verify the evidenceConfirm the expected test inbox received the message, inspect the row state, and check trigger presence, duplicates, last success, and last error.

Copied-sheet test confirmed. Keep the copy as evidence. If anything was unclear, send the exact blocked state or row status to support before using a live Sheet.

What this test does—and does not—prove

It proves that your copied file can reach the reviewed path: duplicate block → corrected exact preview → one-time approval → one send attempt → row and trigger inspection. It does not prove provider-level exactly-once delivery. An ambiguous provider result must remain fail-closed as SEND_UNCERTAIN:.

Check Form Mule migration fit Use the not-sending checklist Review permissions