Wietse Venema:
> Christian R??ner:
> > Would it technically possible to have a smtpd_to_lmtp_proxy option
> > (or however it could be called), that would receive on smtpd and
> > open a connection to its LMTP server, doing cleanup and Co. in
> > memory and wait for the result of the LMTP server? If the LMTP
>
> This does not scale. The problem is that you find out if a recipient
> is over quota AFTER Postfix has already allocated the maximum amount
> of mail server resources.
>
> The scalable way is to make the quota check BEFORE allocating more
> mail server resources. As has been suggested many times over the
> past 13 years, this means using an SMTPD access map or policy daemon
> to block mail for over-quota recipients.
Or use "reject_unverified_recipient", which uses a cache
of previous decisions so it won't hammer the mailbox server.
Wietse
