X env to, nox env to Channel Options

Generation of X-Envelope-to: header lines
The  and   channel options control the generation or suppression of X-Envelope-to: header lines on copies of messages queued to a specific channel. On channels that are marked with the  channel option, the   channel option enables generation of these headers while the   will remove such headers from enqueued messages. The default is ; (note that this default behavior is a change in PMDF V5.0 from previous versions of PMDF). Note that the fact that  also requires the    channel option in order to take effect represents a change of behavior from PMDF V5.1 and earlier.

The (non-standard) X-Envelope-to: header line contains a duplicate of the recipient addresses that appear in the message envelope. The X-Envelope-to: header line for a particular copy of a message contains only the addresses that that particular copy is being sent to; it does not contain all the addresses on the header To: line (except in the simplest case where only a single copy of the message is needed). Also note that there can be envelope recipient addresses that are mentioned nowhere in the header due to the use of things like autoforwarders or blind carbon copies.

New in 6.3, the  channel option no longer requires accompanying use of the    channel option in order to take effect. If used without, the header will simply contain a comma-separated list of all recipients this copy of the message is intended for. This can be useful in situations where the current recipient list needs to be provided as part of the header to some processing agent.

Note that the full recipient list for a message can, if retained at the time of final delivery, reveal the presence of blind carbon recipient to the other, regular recipients. As such, this facility should only be used when it is absolutely necessary.

See also:
 * single Option
 * Headers channel options
 * Channel options