Mike Cardwell:
> If a user attempts to send more email than they are allowed to and the mail
> server starts rejecting it and the users code doesn't handle this case, then
> from the shared hosting companies point of view, it is a problem at the
> users end.
In that case, Postfix can require that the SMTP client uses PHP's
SASL support to authenticate, and with postfwd, Postfix can rate
limit the sender based on SASL credentials and other attributes.
No need to switch mail servers for this. SASL-based rate limits
have been supported since Postfix 2.2, and postfwd has been around
for many years (other policy daemons may also do the job; I
have lost count).
Wietse
