Hello @Maurizio Mancini,
welcome to the Polycom Community.
If you are still seeing this issue please log a ticket with Polycom support as already outlined within this post.
In order to disable Exchange completely please use:
<exchange feature.EWSAutodiscover.enabled="0" feature.exchangeCalendar.enabled="0" feature.exchangeCallLog.enabled="0" feature.exchangeContacts.enabled="0" feature.exchangeVoiceMail.enabled="0" />
In order to raise a support ticket you need to work with your Polycom reseller as they need to do this for you. End Customers are unable to open a ticket directly with Polycom support.
If this is some sort of an Internet discounter please post either your phone's MAC address or your Polycom devices serial so I can look up who would be able to support you. This may not be who you purchased the Polycom device from.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Best Regards
Steffen Baier
Polycom Global Services
I have applied this workaround and can confirm that the warning message has disappeared.
Regards
Robert