Benny Pedersen:
> how will postfix handle connections if recipient domains see ip in rbl
> blacklist, will it be trying agin until all ips on recipient domain is
> tryed ?
Postfix implements the SMTP protocol.
If the remote SMTP server replies with 5XX, the sending Postfix
system returns the recipient as undeliverable.
If the remote SMTP server replies with 4XX, the sending Postfix
system leaves the recipient in the mail queue and retries later.
>From the remote SMTP serrver's point of view, each SMTP connection
has two IP addresses: the client IP address and the server IP
address. Both addresses are in IPv4 form, or both addresses are in
IPv6 form.
In some cases, the Postfix SMTP server will convert (the text form
of) an IPv4-in-IPv6 address to IPv4, so that you won't have have
both forms in your Postfix access maps.
Wietse
