Request: Change behavior when using @mail/bcc

[Hope-Shangrila]

Change the behavior when using @mail/bcc, so that if the sender is a visible destination, often the only name specified on the @mail destination list (rather than the @mail/bcc destination list), the @mail sent to the sender's mailbox retains the list of people it was sent to, including any on the bcc list. It is kind of strange being the sender of the @mail but not being able to see who it was sent to in the @mail when the sender goes back to check it.