In October 2017, popular SMTP plugin Postman SMTP, with 100k+ active installs, was removed from the WordPress repository due to an XSS vulnerability.

This news spread like wildfire. The plugin had not just been removed because of the vulnerability – it had also not been updated in the last sixteen months, making it incompatible with the latest release.

Some security researchers even tried, unsuccessfully, to contact the plugin’s author. While Jason Hendriks, the man behind the plugin, had created an excellent tool for WordPress users, he was unable to maintain the plugin later.

As a WordPress developer and active user of Postman SMTP, I decided to fork the plugin so that all of Jason’s hard work didn’t just end up in the bin. I have named the fork “Post SMTP Mailer/Email Log”, and you can get it from the WordPress repository. Within a few days, the Post SMTP plugin got more than thousands of active installs and now the plugin has more than 200,000 active installations.

Let me take you to a step-by-step guide on setting up the Post SMTP WordPress plugin with Gmail/Google Apps and 0Auth so that Postman SMTP users and others can set it up properly.Table of Contents

Step 1: Install Post SMTP Plugin

Download and install Post SMTP directly from the WordPress plugin repository.

wordpress post smtp plugin

Step 2: Activate Post SMTP Plugin

After installing and activating the plugin, you will see a message inviting you to start configuring the plugin. Click on Settings.

activate post smtp plugin

Step 3: Troubleshooting Screen

This is the main screen of the WordPress Post SMTP plugin. To power the plugin, I have also introduced the handy troubleshooting screen on the right.

troubleshooting post smtp server

Step 4: Start The Wizard

Click on the “Start The Wizard” button, and enter your Email Address and Name.

start post smtp wordpress

Step 5: Gmail SMTP Server

Within a few moments, the plugin will auto-resolve the Gmail SMTP server. After that, click on the Next button.

gmail smtp server

Step 6: Run Connectivity Test

The wizard will run a Connectivity Test and after that, you will see the connection screen.

run connectivity

Step 7: Connect to Mail Server

The wizard will automatically recommend and select: SMTP-STARTTLS with OAuth 2.0 authentication to host on port 587. Then simply click Next.

connect to mail server

Step 8: Client ID and Client Secret

In the Authentication screen, you will need to input two parameters: Client ID and Client Secret to configure it.

smtp wordpress plugin authentication

Step 9: Gmail API in Google API Console

To get the Client ID and the Client Secret, visit Google API Console and log in to your Gmail Account if asked. If it’s for the first time then you need to register your application for Gmail API, or simply Create a project and click Continue.

gmail api for wordpress smtp plugin

After a few seconds, the next screen will appear. Click Go to credentials.

api credentials

Step 10: Create Credential Type

Next in the process is to create credentials for SMTP configuration. Select User data and click NEXT.

google api credentials type

Then, provide the app information like your App NameUser Support Email, and Developer Email Address, and click SAVE AND CONTINUE.

app information

You can skip the next step (Scopes) as it’s an optional step and continue with the OAuth Client ID, where you need to select Web application as the application type.

auth application type

Scroll down the screen and click ADD URI. Paste the Authorized JavaScript Origins URI and Authorized Redirect URI from the plugin Setup Wizard (step 8) to the particular URI field and click Create.

adding authorized uri

Now, you have successfully completed all the steps. You can download your credentials if you wish. Click Done.

auth credentials

Step 11: Add Copy Client ID and Client Secret

Now copy the Client ID and Client Secret and paste them into the plugin Setup Wizard (step 8). Click Web Client 1 (OAuth name) to access your Client ID information.

access client id information

Once you click on the name, you will find the Client ID and Client Secret of your Gmail account that you need to copy.

client id credentials

Next, you need to paste the Client ID and Client Secret to the plugin setup (step 8) and click Next.

providing access credentials of client id and client secret

Then, skip the notification step and finish the setup.

finish wordpress smtp plugins setup

Step 12: Grant Permission with Google

Before you grant permission to your account, change the publishing status from Testing to Publishing. For that, go back to your Google console > OAuth consent screen > Publish App and click Confirm.

push to production

Now get back to your WordPress dashboard > Post SMTP Setup and click Grant permission with Google.

From the dialog box, select the Gmail account you want to use to send emails, and allow all the permissions.

choosing google account

To verify you configured everything correctly, just check that your status matches this one.

postman successful configuration

Step 13: Send a Test Email

The last step is to check and verify that everything is working as expected. Click Send a Test Email option from the Actions section and enter the destination email.

send test email

If everything is configured properly, you should get an email like this one.

smtp test email on gmail account

Final Words!

I hope this article helped you learn how to set up and configure post SMTP on WordPress for free. This is a step-by-step guide where I’ve covered thirteen steps to demonstrate the process.