In message <572BC659.1070401@msapiro.net> Mark Sapiro writes:

On 05/05/2016 02:39 PM, Curtis Villamizar wrote:

...

And BTW - the server was given an IPv4 address before going to production use but the IPv4 is only needed for apache, not for the email setup. The IPv4 may be dropped entirely in the future since I don't use the web interface anymore. Recipients are populated from a database - which is one thing that has always worked fine.

If your email address for @python.org email lists is on a server that only accepts connects at an IPv6 address, you will stop getting all list mail. The current cloud server for mail.python.org is blocked from sending to port 25 at IPv6 addresses.

-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan

In pictures (-> is same host, ---> between hosts):

dual stack IPv6 only

mta2 or mta3 ---> mda -> mailman

mta2 <--- mda <- mailman

On the MTA relay_map is used. On the MDA relayhost is used.

So all mail in or out goes goes by way of one of the dual stack hosts.

It works. Really. :-) Look at the Received headers.

Cutover from an old mailman host to new just means modifying relay_map file on the mta (old to none, then none to new, where none is a fqdn with no host so that mail fails and gets spooled, then sent after the second change).

If the mda/mailman host is also running apache, then I need IPv4 for people who don't have IPv6 to get to the web interface. No one seems to use (or want) the archives on this host. Subscriptions are from a database populated by other means. So the web interface is currently unused (but take it away and someone is bound to try to use it).

Curtis