To utilize your Gmail account with the SMTP addon, you will need to first enable 2-Step Verification for your Gmail account. Access the following URL and enable the 2-Step Verification (option near the center of the page).
After enabling the 2-Step Verification, create an application specific password. The "application specific password" is the password that will need to provided at the PHP Live! SMTP addon. Access the following URL to create an application specific password for "Mail" during the password creation (set the "device" to "Other"). Generate the application specific password and copy the password.
Application Specific Password
Access your PHP Live! SMTP addon and provide the following values to utilize Gmail SMTP (the login and password is your gmail address and the password would be the generated application specific password):
SMTP server: smtp.gmail.com
SMTP port: 587
SMTP encryption: TLS
Click the "Send Verification" button and the system will attempt to send a verification code to your email address. The verification code is needed to complete the PHP Live! SMTP configuration process.