MX records not working. Mail is down due to this

Hi,

Name servers appear in three places, and typically they should all be in synch:
~ The name servers that Route 53 assigns to a hosted zone when you create it. These are the "master" name servers and cannot be changed. Name servers in the other locations usually match these.
~ The name servers in the NS record in the hosted zone.
~ The name servers that are associated with the domain registration. These are the name servers that control which DNS configuration is in use.

For celticland.com, the "master" name servers match the name servers in the NS record, but the name servers in the domain registration are different. This means that you deleted a hosted zone named celticland.com and created a new one. Route 53 assigned a new set of four name servers to the new hosted zone. However, Route 53 doesn't automatically update the domain registration to use the name servers for the new hosted zone.

To fix that, do the following:

1. Get the name servers that Route 53 assigned to the hosted zone when you created it. See "Getting the Name Servers for a Public Hosted Zone" in the Route 53 Developer Guide:

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/GetInfoAboutHostedZone.html

2. Update the domain registration to use the four name servers that you got in step 1. See "Adding or Changing Name Servers and Glue Records for a Domain":

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/domain-name-servers-glue-records.html

After you finish, it might take a couple of days for you to be able to receive email again because DNS resolvers typically cache the names of name servers for two days. For an overview of how DNS works, including the part about resolver caching, see "How Amazon Route 53 routes traffic for your domain":

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/welcome-dns-service.html#welcome-dns-service-how-route-53-routes-traffic

Scott

Thanks Scott. Mail is running again.

Simplified version:
Make sure the Name Servers list for the affected domain under "Registered Domains" matches the entries under the "Hosted Zones"