A comma separated list of addresses for blind carbon copies (optional).
The BCc property specifies a comma separated list of destinations for blind carbon copies of the mail message. A copy of the message is sent to each destination, but no BCc SMTP header is created containing the destination addresses, so individual recipients never see the list of the other recipients.
The task will stop processing the message and log an error if the SMTPServer returns an error code about any email address specified in SendTo or Cc, but it will only log warnings if the same happens with an email address specified in BCc.
This property is not available in the Receiver.