Valid email addresses don't work in Bcc: line of Windows Live Mail 2012 on my Windows 7 Pro computer.  I changed my Live Mail account servers to IMAP & SMTP from POP3, using Microsoft's own instructions, in order to simply continue using the program I'm used to.  Shortly after converting from POP3 the Bcc: address line quit working, returning the error message in my inbox that "Delivery has failed to these recipients or groups:" but the only recipient listed is ";".  It goes on telling me to check the email address(es) and try again, which of course still doesn't work since the address(es) were valid to begin with.

Checking my sent box for the message that failed delivery shows the following under the To column instead of the address(es) used: " ;@.MISSING-HOST-NAME. " my quotes added.  It's as if the program completely ignored by addresses and/or group.  I've surfed the NET for hours but have found no workable solution.