POP3 Account - Outlook is unable to remove the mails.

POP3 Account - Outlook is unable to remove the mails.

Dear ZOHO Team,

We are using POP3 account in outlook.What happening is when i select the  option Leave message on the server in outlook 
Remove from server after 7 days.

But this is not working in ZOHO all the mails is still on the server mailbox.

Can you please tell us why it's not working.


Regards
Amit