current usage of AAAA implicit MX?

S.P.Zeidler spz at
Tue Apr 15 12:59:25 CEST 2008


> So I'm looking for information from people who are currently working 
> in the IPv6-based email world.
> I'm assuming that a number of email sites over in Asia are already 
> IPv6-enabled, and there are probably other enclaves as well. So I'm 
> looking for information on actual email deployment and sites.

I'm offering, amd for domains I happen to know
to be at least partially v6 enabled. Usage common to all three is that
(some) mail servers are dual-stacked and have both A and AAAA to their name
(ie there is no separate v6 name that would appear in MX records).

>   *	How widespread is the use of implicit MX with AAAA records? That
> 	is, how prevalent are email sites that do not have MX records
> 	but do have AAAA records?

I'm not aware of any.

>   *	How big is the existing IPv6-enabled email world?

Probably larger than you expect, with a lot of dual-stacked MX being
around. Enough so that I have seen people abuse "free" tunnels to send
spam, but not enough so that I bother to greylist on v6.

spz at (S.P.Zeidler)

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