An error occurred listing mail in this folder :

Hello I have an issue with email on usermin and I was trying to solve the issue on my own with my little knowledge but I was not successful. I am not able to view the inbox folder for any email account that I have created. it just hangs and tries to load the page but nothing more. After waiting for about 5-10 minutes it returns the following error "An error occurred listing mail in this folder :" and nothing more.

Have any of you faced this issue?

How can I solve it to see all the mailbox inbox files.