We are changing from a cable to a fiber optic connection for internet access at my company. We are getting a new block of static IP numbers so we'll have to change our public IP address. We have a single Kerio Connect email server.

I know I need to change the MX record from the old static IP address to the new one but generally how to you time the change? Besides the MX record, are there other things that need to change as well? This is the first time I've had a change to our public IP address so I'm looking for advice.

We'll have access to both the cable and fiber connections since we don't want to cancel the cable until we know everything is working properly.

Thanks.

Bob,

You'll need to change both the MX record and all "A" records as well. The A record is used by clients (e.g. iPhones) to find the server externally (mail.company.com). You'll also need to update your firewall/router for the new IPs and map them correctly to the existing internal IPs.

As for timing, I usually make my changes in the evening (7-8 PM) as mail volume is lower and the change will have some time to propogate from your DNS host out to the rest of the world. Friday evenings are usually good as the mail volume is lower and the changes have the weekend to propagate.

Cheers,
Jon

Also change your DNS records TTL setting to short and then back to standard time setting will reduce propagation time.

Also this is a great site to see the status of your DNS https://www.whatsmydns.net

Regards