So, this ended up working.

I'd taken parts of stuff from: https://github.com/huskyproject/hpt/blob/master/misc/vtrack/vtrack.pm

Mostly the "do some aliases", the sub me, and that's it so far.

Then in my own filter.pl, I require my crafted functions.pl in the BEGIN {...} section, in my filter sub, I do my usual condition and just post it back through like this:

if (!defined $toarea && $toaddr eq "1:135/300" && $toname eq "Eric Renfro") {
post('NETMAIL', $sfrom, $sto, $from, '1:135/371', $subj, $date, ($attr|TRS|K_S)&~(LOC|ATT|FRQ|URQ|KFS|TFS|HLD|CRA|DIR|IMM|ARQ|RRQ), $text, 3); }

It retains both the original that was sent, and re-posts the new one as a copy and gets packed and delivered to me on my BBS node as I'd hoped, with the same from and to, just different toaddr.

)))[Psi-Jack -//- Decker]
--- SBBSecho 3.07-Linux
* Origin: Decker's Heaven -//- bbs.deckersheaven.com (1:135/371)

Hello Eric,

Monday July 22 2019, Eric Renfro wrote to All:

So, this ended up working.

[...skipped...]

if (!defined $toarea && $toaddr eq "1:135/300" && $toname eq "Eric Renfro")

AFAIK there is no such thing as $toarea in filter.pl. So if you did not define $toarea using $area, 'defined $toarea' is always false. You have to use $area here.

Here is an excerpt from doc/perlhooks.rus:

filter() is called when tossing new messages
The following variables are defined:
variable alias
$fromname $sfrom - the sender's name
$fromaddr $from - the sender's address
$toname $sto - the recipient's name
$toaddr $to - the recipient's address for netmail or undef
$area - area for echomail, otherwise - undef
$secure - current message has been received via SecureInbound
$subject $subj - the message subject
$text - the message text (with kludges)
$date - the date of the message, the variable has two types:
if used as a number, unixtime
if used as a string, the format is fts-1
$attr - attributes as a number
$pktfrom - from whom the current pkt has been received
Return:
$kill = 1 - delete the message
$change = 1 - change fields in accordance with the variables
listed above (including changing kludges automatically)
(except for $area, $secure, $pktfrom :)
If a non-empty string is returned, the message is placed in the badArea

It is not recommended to use attributes and date / time in a string form.

Michael

... node (at) f1042 (dot) ru
--- GoldED+/LNX 1.1.5-b20170303
* Origin: Moscow, Russia (2:5020/1042)