Synchronizing subscribed folders error 0x800CCC0F

Synchronizing subscribed folders error 0x800CCC0F

One of our users (who is accessing Zoho mail through work - main installation - plus computer at home and her phone) is intermittently experiencing the following error:

Task ‘Synchronizing subscribed folders for email@address.com (1).’ Reported error (0x800CCC0F) : ‘Outlook cannot synchronize subscribed folders for email@address.com (1). Error: This IMAP command cannot be sent to the server before the connection was terminated.  If you continue to receive this message, contact your server administrator or Internet service provider (ISP).’

What is this error and how do we fix it? What additional information do you need from us?