mail and IPv6, not The Reg does 240/4

Thu Feb 15 03:26:38 UTC 2024

It appears that Stephen Satchell <list at satchell.net> said:
>On 2/14/24 4:23 PM, Tom Samplonius wrote:
>> The best option is what is happening right now:  you can’t get new IPv4
>> addresses, so you have to either buy them, or use IPv6.  The free market
>>   is solving the problem right now.  Another solution isn’t needed.
>
>Really?  How many mail servers are up on IPv6?  How many legacy mail 
>clients can handle IPv6?  How many MTA software packages can handle IPv6 
>today "right out of the box" without specific configuration?

These days most of them.  The popular open source sendmail, postfix,
and exim all do.  The mail programs on my Android phone and iPad do.
Thunderbird does.

>Does any IPv6 enabled ISP provide PTR records for mail servers?

I'm not sure what you're asking. Every IPv6 mail server has rDNS since
otherwise nobody would accept its mail, same as IPv4.

>How does Google handle mail from an IPv6 server?

Assuming it's authenticated with SPF or DKIM, better than IPv4. All
the mail between Gmail and my system runs over IPv6.

A fair amount of mail from Hotmail/Outlook arrives over IPv6 as well
which is surprising since they don't publish AAAA records for their
inbound mail.

R's,
John