Hmmm - well, depending on your script, you could attach the message as a mime attachment to a new message with a "X-OutCapture" (my own invention - X headers are non-standard) - then when scanning messages in future you can skip this message (which will also appear in the archivedir) OR if the mailbox is local to your server you could simply MOVE the file to the "new" folder under the Maildir - making sure the ownership and permissions are correct... Haven't tested this but think it might work and avoids reprocessing the message as mentioned before.

re-injecting would be by the script though - which would send the message as any script (don't want to mention specific technologies - could bew anything - PERL, PHP, C) and would happen as any normal message send (which is why you have to add a header to prevent filtering your filtered messages again).

m/