What happens to email durring account move?

[dev.null]

I'm setting up two new servers and decommissioning the single old server I've been using.

I went ahead and setup the new servers w/ cluster dns, and hooked in the old server, so now any account moves get synced across them immediately. And yes, I've changed the IPs from my nsX.... servers to the new server IPs within my zone file and w/ the registrar.

So, when I move an account to a new server, instantly all it's DNS is now pointing to the new box, but of course some servers out there will still have the old IPs until their DNS cache grows stale and they query and get the new IPs. So they'll try to deliver to the old server.

Question - what happens to the email?

I think it's best to not delete the account from the old server for a day or so, that way even web queries that still come to the old server will be served up the pages (of course things like the database won't be synced, so any changes there on the old server will be "lost").

Back to the email, so will the old server accept the email and then realize that it's not the root MX server and forward it on to the new server?

Thanks!

(yes, I did try searching around first, you know how many posts come up for "account move email"? dug through them but didn't get anywhere)

 

[cPanelTristan]

The old server won't forward the emails it receives if it accepts them. Those emails are going to either fail or be received by the old machine. I would have suggested changing the MX to have the old machine as secondary MX and the new as the primary MX, then having /etc/secondarymx file created with the domains on the machine all put into that file on the old machine. At that point, the old machine once those records propagate (and you'd want to wait to move the accounts until the propagation completes) will then hold any emails it receives after an account move until it finds the new machine online and forward the emails.

This will then prevent any DNS caching issues for other parties so long as the new machine and old machine show the correct MX on digs (so only propagation for those machines will matter).