All you have to do is select an email from your Outlook web app and drag it to these folders:
VContacts,
VLeads, or
VAccounts. The Exchange Connector will now search for records in Vtiger CRM based on email ID and attach that email if a record is found. If a record is not found, a new record is created in Vtiger CRM, and an email is attached to it. Attaching emails support only one-way sync.
To know more about Exchange Connector, click
here.