Supplementary Information for Messages

In addition to its fields, a message also carries other information.

Address Information

Before sending a message, a program adds these two pieces of address information to the message:

The subject (also called the send subject) of a message directs it to its destinations.
In contrast, the optional reply subject of a message is a return address, to which recipients can send reply messages.

Certified Delivery Information

Certified message delivery (CM) features add more information to a message:

Before sending a message using a certified delivery (CM) transport, a program can set a time limit for certified delivery guarantees on the message.

When a program sends a message using a CM transport, the transport automatically labels the outbound message with two additional pieces of CM information:

The sender name—that is, the correspondent name of the CM transport.
The sequence number of the message.

See Also

Labeled Messages