+ sub addressing setup

[Mark Martinec]

> originally, I've setup all spam marked email to be sent to generic
> spam at mailhost.tld
> 
> that works, but, everyones spam in one account
> 
> I would like to setup spam subaddressing to send amavis picked spam to
> spam subfolder for a user to assess, etc
> 
> I've setup my own address, with voytek+spam at mailhost.tld, it works fine,
> mail gets +spam address, gets to my spam folder
> 
> I'm trying to setup some virtual users on virtual domains as:
> 
> user at vdom1.com
> user+spam at vdom1.com

Using Postfix address classes 'virtual maps' or 'virtual mailbox'
or something else? If using aliases to implement this, one needs
to add 'alias' to a list in propagate_unmatched_extensions.

> when I sent an email (from webmail on mail host) to user+spam at vdom1.com;
> '.spam' folder was created and test email  was delivered to spam
> subfolder, all correct
> 
> BUT, none of real spam email ends up in user at vdom

You mean in user+spam at vdom1.com ?

> I guess I need something additional for virtual domains...?

What is different in mail delivery route between your webmail test
and amavisd re-entry?

> the spam marked emails for my virtuals end up in spam@ email address,

What makes it go there? Quarantinig or rewriting a user+spam address?

> EXCEPT voytek's spam
> 
> I guess I'm missing virtual sub address...? in postfix...?
> (though it seems to work when tested from server webamil)
> thanks for any pointers

This is the main Postfix setting to recognize a delimiter:
e.g.:  recipient_delimiter = +

Address extensions also need to be understood and obeyed by
a mail delivery agent (Cyrus, Dovecot, ...).

  Mark