Am 16. Juni 2023 01:24:41 MESZ schrieb James Cloos via mailop <mailop@mailop.org>: >Would any common MTAs in use have any problems with delivery to a >destination where a subset of its MXs are v4-only and another (non- >intersecting) subset are v6-only?
I tried it for a while and it's somewhat broken... In theory, it should just work. In practice, some people do misconfigure their spamfilters (b) a) If you just have a set of receiving MXes for each protocol, it doesn't matter at all, as long as the sender is able to reach at least one MX for the chosen protocol. b) *some* braindamaged dualstack MX setups reject a connection on v6, if the sending MX is v6-only, but the (dualstack) receiving side tries to find an A record to check against rbls. I have seen some variations of this kind of setup and you can usually work around this, by failover to another sending mx (dualstack or v4 only). Bjørn _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
