Thanks to the Exchange Sync Module for VTiger CRM, you will be able to synchronize your Exchange Calendar (also Office365 and Exchange Online) with VTiger CRM Calendar.
All your scheduled events will be visible both in Outlook and in VTiger CRM. You will be able to modify and delete existing events (and also add new ones): the sync process will replicate modification on both sides (CRM and Exchange).
* PHP min 5.3 +
* PHP Soap extension
* cURL with NTLM support (min version 7.30.0)
* Exchange 2007 or newer or Office365 or Exchange Online
Full documentation: Exchange calendar connector for vtiger