Google has strict security measures it takes to ensure any applications such as Event Master Pro adhere to their standards. Therefore, if you have an email hosted by Gmail, then you may have to follow this process to get your email working.
Use Gmail OAuth2 for Google hosted emails (gmail) emails where you have two step verification enabled or have ‘less secure app’ disabled.
1)The first thing we have to do is make a new project in the Google Developer Console. https://console.developers.google.com/
Once in the console, press Select a project in the top left corner.
2) Once the window opens, press the “New Project” button in the top right corner to create a new project.
3)Set project name for example “email” and submit to ‘create’ button
4) Select your created new project (email) from left.
5) In popup window choose ’email’ row and click on it.
6) Now in new screen click to ‘CREATE CREDENTIALS’ button and choose ‘oauth client id’ from dropdown.