Yes. To understand the working, let us look at the following example of the connectserver.co.in domain which is hosted on O365 and the corresponding Vaultastic domain is connectserver-co-in.vaultastic.com.

Users on O365 and the corresponding Vaultastic users are as follows:

1. amin@connectserver.co.in, amin@connectserver-co-in.vaultastic.com

2. meera@connectserver.co.in,  meera@connectserver-co-in.vaultastic.com

External user 

1. aarav@baya.in

Case 1: O365 user Amin sends mail to O365 user Meera and bcc to external user Aarav

Result BCC Recipient:

  • Mail is delivered to all recipients.
  • Mail is seen in the Sent Items folder of Amin's account in O365 and Vaultastic. From id will be of Amin and To id will be of Meera
  • Clicking Show headers will show the mail headers.
  • Mail headers will show the From id of Amin and the BCC id of Aarav
Case 2: O365 user Amin sends bcc mail to an external user Aarav

Result BCC Recipient:

  • Mail is delivered to external user Aarav
  • Mail is seen in the Sent Items folder of Amin's account in O365 and Vaultastic. The To id will display undisclosed recipient.
  • Clicking Show headers will show the mail headers.
  • Mail headers will show The From id of Amin and the BCC id of Aarav.


Case 3: O365 user Amin receives BCC mail sent by an external user Aarav to O365 user Meera


Result for the BCC Recipient, Amin: 

  • Mail is delivered to the inbox folder of the user Amin. It is seen in O365 and Amin's Vaultastic account.
  • The From id will be of Aarav and the To id will be Meera.
  • Clicking on the Show headers will show the mail headers. 

Case 4: O365 user Amin receives BCC mail from an external user Aarav

Result for the BCC Recipient, Amin: 

  • Mail is delivered to the inbox folder of the user Amin. It is seen in O365 and Amin's Vaultastic account.
  • The From id will be of Aarav and the To id will be Amin
  • Clicking Show headers will display mail headers