On Sunday August 23 2009 04:10:06 Dave Täht wrote: > What I found after fighting with an exchange server that what seems to > work best is assigning my first mx host to be ipv6 only, and my fallback > to be a mx ipv6 and ipv4 host.
My choice is to have the first MX have both the IPv6 and IPv4 addresses, but have a lower priority MX be IPv4-only. This way it should provide a fallback connectivity even if some mailer which thinks it has an IPv6 connectivity but doesn't, then fails to walk through multiple records of a multihomed host name. (even though RFC 5321 requires to try at least two records). Mark
