-----Ursprüngliche Nachricht----- Von: owner-postfix-us...@postfix.org [mailto:owner-postfix-us...@postfix.org] Im Auftrag von Wietse Venema Yes, if the sender is Postfix. Postfix will randomly select from equal-preference IP addresses and IP protocols. This is intentional, so that mail does not get stuck when one path is broken.
Other MTAs may use a different approach, For example, they may try only one IP address per MX record, or they may try IPv4 only after they fail to deliver mail over IPv6. Hi Wietse, is this behavior not described in an RFC? Or is it up to the MTA to deal with the dns answers? Do you know how Microsoft Exchange-Mailservers are behaving in the above setup? Stefan
