> People who configure MX records should read the SMTP RFC, in > particular section 5. "Address Resolution and Mail Handling. > > By design, Postfix enforces sane limits on ALL information. In the > case of SMTP server IP addresses. Such limits protect Postfix > against abusive sites.
Thank you again for your reply, Wietse. Please forgive my relative cluelessness regarding this issue, but could you please elaborate a bit on what you mean? I just read section 5 of RFC 2821, and section 4.5.4.1 (Sending Strategy) as well, which is referenced to in section 5. I understand that the question of whether or not a sender should try different IP's on a multihomed host has been controversial. However by pointing to this RFC you seem to imply more that the MX records aren't configured right to begin with, at least not according to best practice / common sense. Do I interpret you correctly? If so, what would you consider the best way to configure MX records, given the situation that there are 11 incoming SMTP servers required to handle the load and they all have both an IPv4 and an IPv6 address?
