W Wefewences Previous message ID's for conversation threading. When
converting from RFC822 we use References: if present, or
In-Reply-To: otherwise.
- (Who in extnotify spool messages which don't need to know
- other message ids)
Y carbon copY Optional, and only in Mail messages.
0 Error This field is typically never found in a message on
disk or in transit. Message scanning modules are
1 suppress index The presence of this field indicates that the message is
disqualified from being added to the full text index.
2 extnotify Used internally by the serv_extnotify module.
+3 msgnum Used internally to pass the local message number in the
+ database to after-save hooks. Discarded afterwards.
EXAMPLE