Wietse Venema wrote:
I know of no RFC that says only whitelisted clients can send email over IPv6.
Well, it's their policy. I can respect that, if their assumption that senders
should fall back to IPv4 is valid.
2 - Increase smtp_mx_session_limit (default: 2) so that Postfix
will knock more doors.
I guess that is what made their assumption fail. I've upped this limit to 5, and now my messages are waiting to be unlisted at their greylist on their backup IPv4-only MX. Looks promising. Thanks, Pim
