I have own domain and I use it for this ZOHO mail plan. I use eM Client (and Thunderbird) email plan in my PC. My settings incoming server are imappro.zoho.com (port 993). Emails coming in eM Client and Thunderbird only when I restart program. If I change incominserver imap.zoho.com (port 993) then everything are ok. Why so?

What is different imappro vs imap?