Hello,
I am trying to customize the system and I would like to know how to or hints.

I would like to know
1) How to change the Return-Path(? I guess) of emails from mailing list.
When user emails to the list built with IRedmail LDAP Pro default,each member will receive emails from the user's address.
But in general emails from mailing list should show its mailing list address as Return-Path(? I guess) to be replied in the list.
Is it possible to change the Return-Path to the group's mail address? How?

2) How to discard emails from blacklisted but in same mailing list users.
When user A add user B in  same domain with blacklist,user AB are members of a mailing list and user B send emails to the list,
user A receive emails with  ***SPAM*** + original subject.
Is it possible to DISCARD(ignore) the email from user B for user A? How?

I succeeded in DISCARDing direct emails from user B to user A by updating block_amavisd_blacklisted_sender.py

# Reject blacklisted senders.
    if len(valid_amavisd_senders & blSenders) > 0:
        return 'REJECT Blacklisted'
to
# Reject blacklisted senders.
    if len(valid_amavisd_senders & blSenders) > 0:
        return 'DISCARD Blacklisted'

But not succeeded in mailing list.

Could you support me?

Thanks.