I just migrated a web site from one server to another and this domain also has 50+ e-mail accounts. I open new accounts on the new server with same passwords.
I changed DNS pointing to new server.
I am also keeping the old one now in order to miss any e-mail if the e-mail arrives that server.
I am wondering if that's a good idea or not? what should I do here to prevent any e-mail delivery errors if I remove my old app from the old server.
I have just checked the mailboxes on the old server and there are still some e-mail coming there. It has been 12 hours since I changed the DNS.