This feature requires MailerPress Pro.
The Gmail provider sends your MailerPress emails through the Gmail API of a Gmail or Google Workspace account. MailerPress connects with OAuth, Google’s secure authorization system: you never enter your Google password, you only allow MailerPress to send emails on behalf of your account. Gmail suits small volumes: Google limits sending to about 500 emails a day for a free Gmail account and 2,000 for Google Workspace. For regular newsletters, use a dedicated sending service.
What MailerPress needs
MailerPress needs an OAuth client from Google Cloud (an app entry that lets MailerPress request access to your account):
| Item | Details |
|---|---|
| Gmail API Client ID | The client ID of your Google Cloud OAuth client (type “Web application”). |
| Gmail API Client Secret | The client secret of the same client. |
| Authorized redirect URI | The address Google sends you back to after authorization. Shown in MailerPress, in the form https://example.com/wp-admin/admin-post.php?action=mailerpress_gmail_oauth_callback. Add it to the OAuth client in Google Cloud. |
| Permissions (scopes) | https://www.googleapis.com/auth/gmail.send (send emails) and https://www.googleapis.com/auth/userinfo.email (see the account’s email address). MailerPress can’t read your mailbox. |
Create an OAuth client in Google Cloud
Sign in to the Google Cloud console with the Google account you want to send from, or with an administrator account of your Google Workspace.
- Create a project (or select an existing one).
- In the API library, enable the Gmail API for this project.
- Configure the OAuth consent screen (the screen Google shows when you authorize the app): app name, support email and developer contact. With Google Workspace, you can choose the Internal user type to limit the app to your organization.
- Create credentials of type OAuth client ID with the application type Web application.
- In Authorized redirect URIs, paste the Authorized redirect URI shown in MailerPress (see the next section). It must match exactly.
- Copy the client ID and the client secret.
- If the app uses the External user type, publish it (status “In production”). While an app is in “Testing” mode, Google revokes its access after 7 days and MailerPress stops sending.
Connect Gmail in MailerPress
- Go to MailerPress > Integrations, on the Email Service Providers tab.
- On the Gmail card, click Configure.
- Copy the Authorized redirect URI into your Google OAuth client, if not done yet.
- Paste the Gmail API Client ID and the Gmail API Client Secret.
- Click Connect Gmail. The button stays disabled until both fields are filled in. MailerPress saves the settings and opens Google’s authorization screen.
- Choose the Google account to send from and allow the requested permissions. If Google warns that the app isn’t verified, continue: you own the app.
- Google sends you back to your WordPress admin. Return to MailerPress > Integrations if needed: the Gmail card is now under Configured Providers. Turn on its Enable toggle, then click Set as primary provider.
Choose the sender address
The Gmail settings have no sender fields. MailerPress uses the sender chosen in each campaign, or your default sender set in MailerPress > Settings > General (see Customize the default sender name and email address). Use the address of the connected Google account, or an alias added to that account in Gmail. Otherwise Gmail may replace the From address with your account address.
Send a test email
- On the Gmail card, open the three-dot Actions menu and click Send test email.
- Enter a recipient in Send to and click Send.
You should receive an email with the subject “This is a Sending Method Test”. If the test fails, MailerPress shows the Gmail error, for example an expired or invalid access token (401), missing permissions (403) or too many requests (429).
Respect Gmail’s sending limits
Go to MailerPress > Settings > Sending frequency. With Gmail as primary provider, MailerPress shows a warning about Gmail’s daily limits and offers two profiles:
| Profile | Settings | Emails per hour |
|---|---|---|
| Free Gmail (500/day limit) (recommended) | 20 emails every 10 minutes, 2 emails/second | 120 |
| Google Workspace (2,000/day limit) | 50 emails every 10 minutes, 5 emails/second | 300 |
These profiles set the sending pace, not the daily total. The “per day” figure shown by MailerPress is a theoretical maximum: Google’s daily cap still applies, and emails beyond it are refused. Keep each campaign, plus your other emails of the day, below that cap. See How to change your sending frequency in MailerPress.
Bounce tracking
Bounce tracking (automatic detection of emails returned as undeliverable) isn’t available with Gmail: bounce messages arrive in the connected account’s inbox. For automatic bounce handling, use a service that supports it (see Choose and configure your email sending service).
Troubleshooting
- An error message appears at the top of the Gmail settings: MailerPress couldn’t renew access to your account (expired or revoked authorization). Fix the cause, then click Connect Gmail again.
- The connection stops after a few days: your OAuth app is still in “Testing” mode. Publish it in Google Cloud, then reconnect Gmail.
- Google shows a redirect URI mismatch error (redirect_uri_mismatch): the URI in your OAuth client doesn’t match the Authorized redirect URI shown in MailerPress (check http/https and www).
- Emails fail after a number of sends in the day: you reached Gmail’s daily limit. Wait for the limit to reset or switch to another sending service.