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Mailster Gmail Integration
Mailster Gmail Integration

Mailster Gmail Integration

1/5 (1 ratings) 1K+ active installs Updated Oct 15, 2026
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Mailster Gmail Integration adds Gmail as a delivery method for the Mailster Newsletter Plugin for WordPress. Campaigns are sent through the Gmail API from the Google account you authorize.

Use it when you want Mailster to send from a Gmail address instead of your host’s mail server. You connect a Google Cloud OAuth client, authorize the account once, and Mailster uses that mailbox for delivery.

This plugin requires Mailster 2.4.11 or newer, PHP 8.1 or newer, and a Google account. You create an OAuth Client ID in Google Cloud (this is not an API key). Newsletter content is sent to Google through the Gmail API. The plugin requests the https://mail.google.com/ scope so it can send mail and read bounce messages in that mailbox. Gmail applies its own sending limits; Mailster’s guide notes that Gmail is a weak fit for large marketing lists.

Send Mailster campaigns with Gmail

  • Gmail delivery method — Choose Gmail under Newsletter Settings Delivery.
  • Google OAuth — Enter the OAuth Client ID and Client Secret, then authorize the Google account. The settings screen shows the redirect URI to paste into the Google Cloud client.
  • Sending address — After authorization, saving settings copies the connected Gmail address into Mailster’s From, Reply-To, and Bounce fields.
  • Gmail API sending — Mailster messages are sent with users.messages.send for the authorized user. Mailster’s own DKIM signing is turned off for these sends because Gmail handles authentication.
  • Bounce handling — The addon checks that Gmail mailbox for delivery failures and “please remove me” replies, then unsubscribes or bounces the matching Mailster subscriber and removes those messages.
  • Redirect URL filter — Developers can change the OAuth redirect with the mailster_gmail_redirect_url filter.

How it works

  1. Install and activate Mailster Gmail Integration next to Mailster 2.4.11+.
  2. In Google Cloud, enable the Gmail API and create an OAuth client (Web application). Add the redirect URI shown in Mailster’s Gmail settings.
  3. Open Newsletter Settings Delivery, select Gmail, paste the Client ID and Client Secret, and save.
  4. Click Authorize, allow access in Google, and return to Mailster.
  5. Send a test email, then send Mailster campaigns through Gmail.

Setup walkthrough: Send your newsletters via Gmail.