An error occured while executing POP3 command "QUIT". The response was ""

Question

Hi All,

Getting this error when configuring queue for the MSCRM . When I click on the "test access" button  of the  email router configuration manager, getting below mentioned error... for incoming status

"An error occured while executing POP3 command "QUIT". The response was " for one of the queue.

For other queue "Incoming status flashed is success"

Please help on the same.