ActionGmailUpdated May 2026

How do I reply to a Gmail message?

Short answer: Drop the "Gmail → Reply to Message" action anywhere in your workflow, map the inputs from upstream nodes, and publish.

Use this action All 27 Gmail actions

Inputs

The fields this action accepts.

Every field can be mapped from an upstream trigger, AI step, table row, or hard-coded literal.

Field	Type	Required	Description
Original Message ID messageId	string	Required	Gmail message ID — the hex string Gmail assigns to each message. Find via List Messages. Not the RFC822 Message-Id header.
To to	email	Required	To. e.g. "recipient@example.com"
Reply Body body	html	Required	Reply Body. e.g. "<p>Thanks for your email...</p>"
CC cc	string	Optional	CC. e.g. "cc@example.com"
BCC bcc	string	Optional	BCC. e.g. "bcc@example.com"

Sample request

{
  "messageId": "e.g. 18a1b2c3d4e5f6",
  "to": "recipient@example.com",
  "body": "<p>Thanks for your email...</p>",
  "cc": "cc@example.com",
  "bcc": "bcc@example.com"
}

Returns

{
  "id": "msg456",
  "labelIds": [
    "SENT"
  ],
  "threadId": "thread123"
}

Use these fields in downstream nodes for routing, logging, or error handling.

Triggered by

Apps that pair well as the trigger for Reply to Message.

Any of these apps can fire this action as part of a workflow.

Slack → Gmail

13 Slack triggers

Google Sheets → Gmail

2 Google Sheets triggers

FAQ

Questions about Reply to Message.

What does the Reply to Message action do in Gmail?

Replies to an existing email message, preserving the thread (In-Reply-To and References headers). The default outbound action for autoresponders or AI handoffs.

What inputs does Reply to Message require?

Required: Original Message ID, To, Reply Body. Every input accepts a static value or a variable from any upstream node in your workflow.

Can I use dynamic inputs from earlier workflow nodes?

Yes. Any field on this action can pull values from upstream nodes, whether that's a form response, a trigger payload, an AI output, or a lookup result.

What happens if Gmail returns an error?

The workflow pauses on the failed node, the error message is captured in the run log, and you can retry the run with one click. Auto-retry policies are configurable per workflow with exponential backoff up to 5 attempts.

Does Reply to Message support batch operations?

Yes. Run Reply to Message inside a Loop node to process arrays. Tiny Command handles Gmail's rate limits automatically so you don't have to throttle manually.

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