Q:

Postfix forward specific mails from HOLD queue

Is it possible in postfix to forward messages from the hold queue by referencing to them by their file name?
The best way would be by a terminal command. 
Even better would be a python command. 
If that's not possible editing the main.cf would be a considered option.
Background:
I have a python script which gives me a dynamic list of filenames of the mails in the hold queue which should be forwarded to a specific address for further examination before being delivered to their final destination.
e.g. of a file list from the hold queue
49C0B406D7
1F3BD40685
9F847406D8
61C63406D6

A:

Just use shell command
postcat -qbh queueid | sendmail -f sender forward_address@example.com

Source: man postcat, man sendmail and this thread Postfix: change sender in queued messages

