Gmail Alias Auto-Responder Deployment Guide

This guide details the deployment of a Google Apps Script solution that automatically sends an acknowledgement reply from a designated Gmail alias. This script monitors incoming unread emails for the specified alias, replies with a custom message, and applies a label to prevent duplicate responses.

Pro Tip: This solution is excellent for low to moderate email volumes. For a long term professional solution or if email volume increases, we strongly recommend migrating to a dedicated Ticketing System (e.g., Chatwoot (cloud and selfhosted options), Zendesk, HubSpot Service Hub)

1. Prerequisites and Setup

Before starting, ensure you have the following:

• A Google Account where the alias is configured.
• The Alias Email Address must be set up in your Gmail settings under “Send mail as.”
• A Gmail Label must be created for tracking.

Create the Gmail Label

• Open your Gmail inbox.
• On the left-hand menu, scroll down and click More, then click Create new label.
• Enter the label name: Auto-Replied (or the name you plan to use in the script’s PROCESSED_LABEL variable).
• Click Create.

2. Create the Apps Script Project

The core of this solution runs on Google Apps Script.

• Go to script.google.com.
• Click New project (or + New).
• In the code editor, delete any boilerplate code (e.g., function myFunction() { … }).
• Paste the complete JavaScript code provided below into the Code.gs file.
• Rename the project (e.g., Alias Autoreply).

3. Configure the Script

Edit the CONFIGURATION section at the very top of the script with your specific information.

4. Set Up the Time-Driven Trigger

A trigger is required to run the script automatically on a schedule.

• In the Apps Script editor, click the Triggers icon (it looks like a clock) in the left sidebar.
• Click the + Add Trigger button in the bottom-right.
• Choose which function to run: processAliasEmails
• Choose which deployment should run: Head
• Select event source: Time-driven
• Select type of time-based trigger: Minutes timer
• Select minute interval: Choose Every 5 minutes (or Every 10 minutes).
• Click Save.

5. Authorize the Script (One-Time Action)

The first time you save the trigger, Google will require your permission to allow the script to access your Gmail.

• An “Authorization required” window will pop up. Click Review permissions.
• Choose the Google account that holds the alias.
• You will see a “Google hasn’t verified this app” warning. This is expected since it’s your personal script. Click Advanced, then click Go to Your Script Name.
• Review the permissions and click Allow.

The script is now deployed and will automatically check for and reply to unread emails sent to your alias on the set schedule.

See the code in our GitHub Repository https://github.com/wannaco/Gmail-Auto-Responder-Email-alias

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