mattanja
I know this is old, however, I am here trying to find a solution.
I also had your settings in my past email server. I tried to do this:
my data is a subdirectory of /opt/mailcow-dockerized
data/conf/postfix/extra.cf
myhostname = THIS_ALREADY_HAD_MY_HOSTNAME
maildrop_destination_recipient_limit = 1
and adding the O flag to maildrop in data/conf/postfix/master.cf
maildrop unix - n n - - pipe flags=DROhu
user=vmail argv=/usr/bin/maildrop -d ${recipient}
Restarted postfix.
Header is NOT added.
My issue:
I have some very elaborate sieve filters that I used on my former host, my primary domain uses a catch all alias.
I give out my email as follows:
apple.com@example.com
Where example.com is my domain. Then I can setup sieve filters to FILE all email sent to apple.com. When the email address gets too spammy, I discard. I also have some that compare the ORIGINAL_TO to the SENDING domain, for example, emails sent to apple.com@example.com will automatically discard emails sent FROM gmail.com.
It appears that rspamd does add the original_to in as PREVIOUSLY_DELIVERED inside the X-Spamd-Result header. However, I need to work on a sieve filter that extract this value (if possible). Also, I am not sure how reliable the field is.
Anybody figure this out? We must not be the only ones.