You haven't provided the complete configuration, but still I'll answer.

You are using POP Server, but the server name is 'imap.gmail.com'.
Also, you need to check 'SSL/TLS' (specifically for GMail).

This link would help you.
https://support.google.com/mail/answer/7104828?hl=en

Dear,

Now it worked when I choose the right follower and thread ID. But I am not clear the follower feature and thread ID. Could you make me clear more?

THanks

Still

fetching same issue anyone here. kindly provide the solution on this issue.