GET api/2.0/mail/settings/cacheMessagesEnabled
Returns a flag that specifies whether to cache unread messages or not.
This method doesn't have any parameters.
GET api/2.0/mail/settings/cachemessagesenabled
Host: yourportal.onlyoffice.com
Content-Type: application/json
Accept: application/json
Boolean value: true - the flag is enabled, false - the flag is disabled