TRANSFER Programming Manual

Blind Copy (BCC) Recipients (P2)
X400 Services
6–20 069138, Update 1 to 040970 Tandem Computers Incorporated
Blind Copy (BCC)
Recipients (P2)
Blind copy (BCC—blind courtesy copy) recipients are TRANSFER or X400 recipients
whose names should not be disclosed to other (primary or copy) recipients of a
message.
Note Restriction of BCC recipients is the responsibility of the recipient client or UA. There is no guarantee that
the destination domain restricts access to BCC recipient names.
A client can specify up to 9999 BCC recipients. You can add BCC recipients to
packages with any item type; however, when a message is exported to one or more
X400 recipients, the distinction between BCC recipients and TO and CC recipients is
valid only if the package is a mail package.
BCC recipient names occupy two records—one for delivery (P1) and one for display
(P2). The use of a distribution list as a recipient illustrates how X400 uses these
records:
The TRANSFER delivery system expands the distribution list and uses each
individual name for delivery.
The recipient X400 UA displays the distribution list name instead of a lengthy list
of members.
When exporting packages with BCC recipients, the gateway generates two types of P1
messages:
1. The first message contains the P2 message without the BCC recipients specified.
This message is sent only to the TO and CC recipients.
2. The second message contains the P2 message with the BCC recipients specified.
This second message goes only to the BCC recipients. Therefore, BCC recipients
are aware of each others' identities.
The total number of recipients for a package with X400 recipients must be no more
than 32,768. You can specify TRANSFER distribution lists as BCC recipients.