Unable to connect

I recently installed Postie and am trying to connect to my Gmail account. I am getting an error message when I click “Test Config.” I have checked the username and password.

The error message is: “Unable to connect. The server said: The username and password provided were not accepted for the IMAP server imap.gmail.com on port 993”

Initially, I received an error email on my gmail account prompting me to allow access to less secure apps. I did so.

My settings are Sockets – IMAP-SSL Port 993 – USERNAME@gmail.com, and the password, which I have checked carefully to be sure it is correct.

I’m running Postie 1.9.2 on WordPress 4.8.1.

Is it possible I’ve been locked out for too many attempts, and I should just wait a day?

Thanks!