- Login to gmail.
- Go to setting ( https://www.google.com/settings/security/lesssecureapps)
- Allow less secure apps.
- After mail sent you should disable access.
it only contain one space like Shashank abc@gmail.com Shashank_Gupta abc@gmail.com
Shashank Gupta abc@gmail.com (this will not work because it contain extra space between Shashank and Gupta)