incoming smtp from v6 addresses

Bernhard Schmidt berni at
Fri Jan 6 19:16:50 UTC 2012

Randy Bush <randy at> wrote:
> for incoming mail that is *accepted*, i.e. not stuff like
>     2012-01-04 00:37:28 REJECT because listed in
>     2012-01-04 00:37:28 H=( [] F=<pedrom at> rejected RCPT <owner-radiusext at>: blocked because is in  blacklist at Mail from blocked using Trend Micro Email Reputation database. Please see <>
>     2012-01-04 00:37:28 no host name found for IP address
>     2012-01-04 00:37:29 REJECT too many bad recip
>     2012-01-04 00:37:29 REJECT because listed in
> 7.8% is over ipv6 transport
> but only 2% of outgoing deliveries are over ipv6.
> what do other folk see?

Main inbound MX for a large educational institution sees around 5% of
mails coming in via IPv6. Might be a bit biased due to holiday season.

Outbound is mostly running on legacy servers without IPv6, yet :-(


More information about the NANOG mailing list