First Create a mailing list within 100 email, not more than. After create a new campaign you will redirect to campaign settings , here under SMTP settings set the below mentioned data. Delay between sending emails from SMTP :- 30 SECOND SMTP Server Address :- smtp.gmail.com From mail id :- your gmail mail id (yourmail@gmail.com) Mail login id :- your gmail mail id (yourmail@gmail.com) Mail login id :- your gmail mail password/less secure password (please see the details below) port :- 465 SSL :- enable TLS :- disable OR port :- 587 SSL :- disable TLS :- enable Compleate all settings, first put your normal gmail login password into password field then click on "Test Connection" button, it will send a mail to our server if everything is correct then you will get success message eithir you will get SMTP error message. If you get error then you need to change some of the security and permission level settings under your Google Account Security Settings. (1)Make sure that 2-Step-Verification is disabled. (2)Turn ON the "Less Secure App" access or click here. (3)If 2-step-verification is enabled, then you will have to create app password for your application or device. after create less secure password, copy this password and paste it into your login password field and again click on TEST Connection Button. After success set other field like mail subject , from name , select mailing list, then click on 'SAVE' button to save your settings and write your html mail body.