Sending Mautic Email Messages via OAuth 2.0 Client | Google Cloud

EasyApache 4
My Mautic version is: 45_mautic-449
My PHP 80, PHP 8.0.29-1.1.3.cpanel
extention: php80-php-fileinfo
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OS: AlmaLinux v8.8.0 STANDARD kvm
cPanel Version 112.0.5

Hi everyone,

Your problem
Does Mautic enable sending email messages via OAuth 2.0 Client? If so, could you please provide configuration instructions?


Yes email can end email via API. The exact config will depend upon what service you want to use to send email.

Look under settings cog → configuration → email settings. Set up is pretty self explanatory.

Hi robm,

A careful analysis of Mautic’s Configuration > Mail Send Settings > Service to send mail through the Google G-Mail API tunnel. Can you confirm these steps as follows:

How to configure Gmail API settings for sending outbound email messages from a Mautic client to a Firebase Gmail API server:

Here are the step-by-step instructions to set up Firebase project and enable the Gmail API:

Guide to Configure OAuth 2.0 Client with Mautic

Step 1: Log in to your Mautic account and access the admin dashboard.

Step 2: Navigate to the “Configuration” section in the top menu.

Step 3: From the dropdown menu, select “Plugins.”

Step 4: Search for “OAuth” and click on “OAuth 2 Two-Legged Authentication” to enable it.

Step 5: After enabling the plugin, click on the gear icon (settings) next to the “OAuth 2 Two-Legged Authentication” plugin.

Step 6: Fill in the following details:

  • Enabled: Check the box to enable the OAuth 2 Two-Legged Authentication plugin.
  • Client Key: Enter the OAuth client ID obtained when creating your OAuth client.
  • Client Secret: Enter the client secret associated with the OAuth client.
  • Authorize URL: Enter the authorization URL specific to the OAuth provider (e.g., Gmail API).
  • Access Token URL: Enter the access token URL specific to the OAuth provider.
  • Redirect URI: Enter the URL where users will be redirected after granting access.

Step 7: Click the “Apply” button to save the changes.

Step 8: Configure OAuth settings for each email service. Go to the “Email Settings” in the Mautic dashboard.

Step 9: For each email service, select the OAuth 2.0 client you created from the dropdown list.

Step 10: Save the changes.

Step 11: Proceed to create email campaigns and use the OAuth 2.0 credentials to send emails through the selected email service.

The guide provides a step-by-step process to configure OAuth 2.0 client with Mautic for secure authentication when sending email messages. The steps involve enabling the OAuth 2 Two-Legged Authentication plugin, entering the OAuth client details, including the client ID and secret, and configuring the authorization and access token URLs. After saving the settings, you can assign the OAuth 2.0 client to specific email services and proceed to create email campaigns using OAuth 2.0 authentication.


I have not used the Gmail API before so can’ t help further. I use the the Amazon SES API and it works flawlessly.

What is the daily quota of deliverable email set by Amazon SES API? We have a daily quota limit of 2 million with Google Cloud.

50 000 per day for me but you can request a higher daily quota

Hi, everyone,

Where is the Gmail Extension Secret official Mautic documentation to send email messages via Gmail API?

See the attached screenshot image.

Error message reads: “Connection could not be established with host :stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages: error:1408F10B:SSL routines:ssl3_get_record:wrong version number " (code: 535) (code: 535) >> RSET << 250 Reset OK.”

See the captured screenshot image:

The error indicates a problem with SSL connection establishment to the server. This could be due to SSL version mismatch, outdated libraries, incorrect encryption protocols, firewall or proxy issues, or SSL certificate problems. To resolve the error, can you provide instructions on how to check the application’s SSL/TLS plugin configuration is up to date and compatible with the server’s requirements?



AWS replied to my request to increase the daily Amazon SES API quota to 2 million with the following questions:

"If the request is to increase the limit for API Gateway, then please reply back to us with the below details:

Limit increase request 1
Limit name:
New limit value:

Can you respond with a Mautic solution?