[Mailman-Developers] Storing extra data during pipeline processing

[Juraj Variny]

Hello,

I am adapting the GPG patch for mailman 2.1.x for our project and want to gather 
some related data in Approve and Scrubber handlers and use them in the archiver. 
Can you please advise me how to attach some metadata to a message to use it in 
later stages? 

Also noticed Scrubber being called multiple times per message (from normal pipeline, 
from digester, from archiver). I want to verify GPG signatures of the attachments in 
scrubber and redoing it multiple time is wasteful of system resources, I want  to attach 
some metadata after the first checking to prevent it, too.

I have tried already to use msgdata parameter or adding headers to message itself, 
but was not successful so far. I was thinking about adding external database and 
putting the data there by message ID, but sure there must be a better way? I hope to 
publish the code some day, too.

Juraj