Email over v6

Thu Jul 8 18:37:07 UTC 2010

On Jul 8, 2010, at 2:21 PM, Dan White wrote:

> On 08/07/10 19:04 +0200, Mikael Abrahamsson wrote:
>> On Thu, 8 Jul 2010, Brielle Bruns wrote:
>> 
>>> By default, at least on Debian, TLS and IPv6 (if available, even if only using link local addresses) are on by default, so there's not too much that needs to be done to use TLS on the SMTP side.
>> 
>> TLS wasn't enabled on my Debian using Postfix, so I guess it depends on  more factors than just "running Debian". IPv6 seems to be on by default,  yes.
> 
> I can confirm that STARTTLS was enabled out of the box on my Debian unstable
> system... using the snakeoil cert of course.
> 
> IPv6 (port 25 incoming) was not enabled out of the box. I needed to add
> "inet_protocols = ipv4, ipv6" to enable it.

I figured I would share actual data for everyone here, roughly 1:4.22 messages that are handled by my system go over some sort of IPv6 transport.

(excluding connections from itself-to-itself.. i should make these be IPv6)

puck:~> grep sm-mta /var/log/maillog | grep IPv4 | grep -v 204.42.254.5 | wc -l
   22696
puck:~> grep sm-mta /var/log/maillog | grep IPv6 | wc -l
    5371

The technical community lists are good fodder for this data.  (eg: nanog, *-nsp) 

I do wonder if gmail.com gives out AAAA addresses for their MX, and the same for other mail solutions.

This seems like something that is a no-brainer for me, as latency on email isn't a big deal where for HTTP transactions it can be.

- Jared