Anyway my settings is as follows:
Login to Prestashop administration page>>Advance parameters>>Email
Send email to = Customer service
Set my own SMTP parameters (for advanced users ONLY)
SMTP server: smtp.googlemail.com
SMTP username: firstname.lastname@example.org
SMTP password: my email password
Try to test sending email and an error such as below will be prompted.
Error: Please check your configuration
Authentication failed using username 'email@example.com' and password '**********'
At the same time i was receiving a notification from Gmail that "Sign-In Attempt Prevented" as below
This is because prestashop is consider less secure application and Gmail have blocked it. Fortunately you can unblock this by allowing the less secure apps to work by accessing this google page "Allowing less secure apps" and click on the "Turn On" radio option.
Once it is turned on i have received a notification in gmail that "Access for less secure apps has been turned on" like below.
Once you have received this notification go back to Prestashop administration page>>Advance parameters>>Email and retest the email send. This is then it's a success. Oh hell yeah it was a long headache but it's fine now.