To allow MS-Outlook or other 3rd applications to work with Gmail,


Please click here . The hyperlink will take you to https://myaccount.google.com/ page, click on sign-in & security 


Turn "ALLOW LESS SECURE APPS" to ON  (See the Screenshot below)


AllowLessSecureApps



Note: This setting is hidden if your administrator has locked less secure app account access,for more information click here



Regards

Google Apps Team

Brio Technologies Pvt Ltd