The new server, Exchange 2010, will be across a Metro E network, with a public IP of 18.104.22.168, and a private IP of 10.1.1.1. What are best practices for doing this with minimal downtime?If you move the mailbox store to the new server, can you still keep sending and receiving from the old server? If you simply update the public MX record to point to 22.214.171.124, which takes about 24 hours, what happens in the meantime?However, due to DNS cashing it will take a while for the changes to get out to clients.This will be more of a problem for frequent clients than occasional clients.If you are using a CNAME record or other DNS, you will not be able to make a change to the MX records within the 1&1 Control Panel and will need to make this change with your current DNS host.Please note that mail server priority is usually set in multiples of 10 with the lowest number taking top priority (similar to golf).You can work around this by pre-populating your data.
Before performing a DNS change, it is common practice to lower the TTL from it's regular value (a day or more, typically) down to something really small, like 5 minutes.To edit the MX Records you must supply at least two mail server addresses.The addresses must be domains or subdomains and cannot be IP addresses.I am trying to estimate whether it is realistic for me to change the IP of a mail server overnight or will this mess with people retrieving their email the day after.
Basically, the facility where the mail server is will be changing its IP pool and this forces me to have to change the A and MX record for the mail server.
If you are only able to access your mail server via its IP address, you must enter an IP address for your domain's MX Record instead.