# Google Workspace / Gmail Source: https://catalystgroup.gg/docs/email-delivery/mailer-gmail/ Updated: 2026-10-19 · By Duane Garner Connect CRM-NG SMTP to Gmail or Google Workspace with your own Google OAuth app, so your site sends through your Google account. This guide shows you how to send your WordPress email through a Gmail or Google Workspace account. It suits small sites that send a modest number of messages and already use Google for email. The **Google / Gmail** mailer uses the Gmail API through an OAuth app you create in the Google Cloud Console. It asks for one permission, `gmail.send`: the site can send mail but not read your inbox. Google returns straight to your own site; nothing passes through any other service. > **Daily limits:** Google caps how many messages an account may send each day. For newsletters or large batches, use a dedicated sending service. See [Choosing a mail service](https://catalystgroup.gg/docs/email-delivery/choose-a-mailer/). ## Before you start - A Gmail address or a Google Workspace mailbox that will send the email. - Access to the Google Cloud Console with that account (for Workspace, your admin may need to allow you to create projects). - Administrator access to your WordPress site, and your site served over HTTPS. The settings screen's **Guided Gmail Setup** list links to each Google page used below. ## Step 1: Create the Google Cloud project and enable the Gmail API 1. Open the Google Cloud Console Go to `https://console.cloud.google.com/` and sign in with the Google account that owns the sending address. 2. Create or pick a project Open the project picker at the top of the page and choose **New project**. Name it, for example "Website mail", and create it. Make sure the new project is selected before you go on. 3. Enable the Gmail API Open **APIs & Services → Library**, search for "Gmail API", open it and press **Enable**. ## Step 2: Set up the OAuth consent screen Google now groups these pages under **Google Auth Platform** (older layouts call it **OAuth consent screen**). Look for the pages named **Branding**, **Audience**, **Data Access** and **Clients**. 1. Start the consent screen Open **Google Auth Platform → Branding** and press **Get started**. Enter an app name (your site name is fine) and a support email address. 2. Choose the audience On Google Workspace, pick **Internal** (only your organisation can use it, and Google does not review it). On a personal @gmail.com account, pick **External**. 3. Add contact details and finish Enter a developer contact email, accept the policy and create the app. 4. Add the gmail.send scope Open **Data Access**, press **Add or remove scopes**, find `https://www.googleapis.com/auth/gmail.send`, tick it and save. No other scope is needed. 5. Publish an External app If you chose External, open **Audience** and press **Publish app** so its status reads **In production**. An app left in **Testing** issues sign-ins that expire after about seven days, and sending then stops. > **Unverified app warning:** An unreviewed External app shows a warning when you authorise it. As you are the only person signing in, continue with **Advanced → Go to (app name)**. You do not need Google's review to send from your own account. ## Step 3: Create the OAuth client 1. Copy the redirect address from WordPress In WordPress, open **CRM-NG SMTP → Settings → General**, set **Mailer** to **Google / Gmail**, and copy the **Authorized redirect URI** with the copy button beside it (**Copy URL to clipboard**). It points to your own admin area. 2. Create the client Back in Google, open **Clients** (or **APIs & Services → Credentials → Create credentials → OAuth client ID**) and choose the application type **Web application**. 3. Paste the redirect address Under **Authorized redirect URIs**, press **Add URI** and paste the address exactly as copied. Leave **Authorized JavaScript origins** empty. 4. Save and copy the keys Press **Create** and copy the **Client ID** and **Client secret** somewhere safe. ## Step 4: Connect in CRM-NG SMTP 1. Set your sender On **CRM-NG SMTP → Settings → General**, set **From Email** to the Gmail or Workspace address you are connecting (or a verified alias, see below) and set **From Name**. Tick **Force From Email** if other plugins keep changing the sender. 2. Paste the keys Paste the value into **Client ID** and **Client Secret**. 3. Save first Press **Save Settings**. Until you save, the **Authorization** row says "You need to save settings with Client ID and Client Secret before you can proceed." 4. Authorise the account Press **Allow plugin to send emails using your Google account**. Google asks you to choose the account and approve sending. Approve it, and you return to the settings page. 5. Check the connection The button changes to **Remove OAuth Connection**, sometimes with **Connected as** and your address. ## Send-from alias You can send as another address that belongs to your Google account, such as `hello@yourdomain.com`, as long as Gmail already accepts it as a "Send mail as" address. 1. Add the alias in Gmail In Gmail, open the gear menu → **See all settings → Accounts** (on personal accounts the tab is **Accounts and Import**). Under **Send mail as**, choose **Add another email address**, enter the alias, and keep **Treat as an alias** ticked. 2. Verify it Gmail sends a confirmation code or link to the alias address. Complete it. On Google Workspace, an admin may first need to add the address as an alternate email for your user in the Google Admin console. 3. Use it in CRM-NG SMTP Set **From Email** on **CRM-NG SMTP → Settings → General** to the alias and press **Save Settings**. 4. Allow several aliases To let different plugins send from different verified aliases, leave **Force From Email** unticked and set each plugin's sender to one of your aliases. > **Who decides the From address:** With send-only permission the plugin cannot read your alias list, so Gmail decides: a verified "Send mail as" address is kept, anything else becomes your main address. A test arriving from the main address means the alias is not verified yet. ## Send a test email Open **CRM-NG SMTP → Tools → Email Test**, enter your own address in **Send To**, and press **Send Email**. Open the message in Gmail, choose **Show original**, and check that SPF, DKIM and DMARC all say PASS. More detail: [Sending a test email](https://catalystgroup.gg/docs/email-delivery/send-a-test-email/). On your own domain, make sure your SPF record includes `_spf.google.com` and that DKIM is switched on in the Google Admin console. See [Adding DNS records](https://catalystgroup.gg/docs/email-delivery/dns-records/). ## Troubleshooting - Sending stopped after a few days, or after a password change: [invalid_grant: token expired or revoked](https://catalystgroup.gg/docs/email-delivery/error-invalid-grant-token-expired-or-revoked/) - Authorisation fails straight away: [invalid_grant: bad request](https://catalystgroup.gg/docs/email-delivery/error-invalid-grant-bad-request/) - Google rejects the client: [unauthorized_client](https://catalystgroup.gg/docs/email-delivery/error-unauthorized-client/) - The Gmail service is switched off for the user: [Mail service not enabled](https://catalystgroup.gg/docs/email-delivery/error-mail-service-not-enabled/) - A certificate problem on your server: [cURL error 77](https://catalystgroup.gg/docs/email-delivery/error-curl-error-77/) - General failures: [Gmail could not authenticate](https://catalystgroup.gg/docs/email-delivery/error-gmail-could-not-authenticate/) - Mail arrives in spam: [Emails landing in spam](https://catalystgroup.gg/docs/email-delivery/emails-landing-in-spam/) To start again or link another Google account, press **Remove OAuth Connection** and authorise again. ## Related - [Choosing a mail service](https://catalystgroup.gg/docs/email-delivery/choose-a-mailer/) - [Sender name, address and the Force settings](https://catalystgroup.gg/docs/email-delivery/sender-name-and-address/) - [Using Force From Email](https://catalystgroup.gg/docs/email-delivery/force-from-email/) - [Adding DNS records: SPF, DKIM and DMARC](https://catalystgroup.gg/docs/email-delivery/dns-records/) - [Debug events](https://catalystgroup.gg/docs/email-delivery/debug-events/)