Hi, im having an issue with zoho. I've successfully setup a private mail server that through POP3 retrieves zoho's email from my 3 domain mailboxes. 2 of them work perfectly fine, but the 1 with the most emails, after 6 hours of retrieving a large email portion from the inbox it gave me "Authentication has failed"

I didnt change anything on my configuration or network, and all the mailboxes have app-specific passwords. 

It was perfectly working retrieving and suddenly stop without any changes. Could you help?