IMAP states SERVER DISCONNECT, but my IMAP port is open

IMAP states SERVER DISCONNECT, but my IMAP port is open

After using Zoho CRM for a few months, and the IMAP integration working well, I went to update the password on my account and saw that rather than syncing sucssesfully (or not), I was given a SERVER DISCONNECT error. I checked with my IT department, who stated taht your firewall and IMAP ports for the internal email server are open. However, when I checked my host name, the port is closed.

Any idea what is causing this, or how it can be resolved??

Thanks in Advance!