I'm migrating my vpopmail server to a new machine. The DNS zones
fortunately do not have to be moved.
My tentative plan for how to achieve the transition is as follows.
(1) set up the new server with identical vpopmail domain/user structure
(2) have the new server ready to receive SMTP for these domains, but with no
MX pointing to it yet
(3) set up the old server to route ALL outgoing SMTP through the new server
At that point everything is basically set up for a transition, but nothing
has really changed yet except how outgoing SMTP is being routed.
(4) On the old server, delete all domains currently delivered locally there,
but still accept incoming messages for those domains. (Also retain maildirs
and contents for later copying. So I can't just vdeldomain.) The idea is
that incoming messages still go through the old server, but as soon as the
local domains are gone they get passed on to the new server with all other
(5) Copy all residual POP directory contents left on the old server to the
(6) Re-point the MX to the new server. Actually this is probably just an A
record change since the MX hostname will remain the same.
(7) Update all other relevant A records that end-users have entered into
their MUA configurations.
I'm not sure of a couple things in the above plan.
(a) Basically how do I achieve step (4) above? Do I manually empty the
assign file and/or virtualdomains files since I need to retain the POP
directories and so can't use vdeldomain?
(b) On the new server, is there any advantage (or necessity) to accepting
delivery for the domains but deferring the actual local delivery until the
old POP contents are copied over first?
Thanks for any thoughts.