[Mailman-Users] Migration to a new server: recommendations for testing the new Mailman server before changing DNS records; also how to avoid lost/bounced messages during change-over?

[David]

On Mon, Jul 8, 2013 at 6:27 PM, Mark Sapiro <mark at msapiro.net> wrote:

>
> >
> > So far all I did was:
> > 1. create a ~/.mailrc file with contents:
> >
> > set smtp=localhost
>
>
> If that tells mailx to send via smtp to localhost, that's good.
>
>
> > 2. edit /etc/postfix/main.cf <http://main.cf> and change mydestination
> > to the line below:
> > mydestination = localhost, localhost.localdomain
>
>
> If I understood correctly, this is not what you want. My understanding
> is you have an old (current) box with a domain and an IP and DNS for the
> domain pointing to the IP, and after the switch the domain and IP will
> be those of the new box, but for now, the new box has a different IP.
>

The old/current box is live. It has a domain, IP and matching DNS records
and it works as it should.

The new/migrated box is not yet live. We have copied Mailman to it, but we
need to test. The migration process is a bit complex because of opendkim
settings and a few other things, so I think testing first is a good idea
before we go live.

When we finish testing, I will move the old IP address to the new box (swap
IPs).



>
> If this is the case, you should not be making any changes to main.cf
> over what you want after the switch, i.e. it should look like that on
> the old box.
>

OK. I misunderstood.


>
> Now, in this configuration, list mail should be delivered locally, so if
> you send mail from the local MUA on the new box to a list address, the
> MUA will deliver it to the local Postfix and that in turn will deliver
> it to the local Mailman.
>

For some reason, it is not working. I will review the settings.