DNS stands for the Domain Name System. DNS stores the information necessary—namely the IP address, or a way to find an IP address—to locate and resolve the name to the associated content. Each entry has a few attributes:
ARecord: The entry directly resolves to an IPv4 address.
AAAARecord: The entry directly resolves to an IPv6 address.
CNAMERecord: Resolving this entry will instead resolve to whatever the value of this record resolves to. For instance, a
some-infrastructure.example.comwill resolve as if there were duplicate entries for the same IP address at both
TXTRecord: The entry is not interpreted, but instead hold arbitrary data. This is useful for using DNS for other utilities, like SPF/DKIM email validation.
First, check whether your SPF/TXT record has a valid value; there are tools around the internet (e.g. this one) to test configurations. If those tools show that the SPF entry is valid, check the configuration of the mail server.
If you used a high TTL value, you may wait quite a while to see the results around the world. Setting a low TTL for an entry is crucial to seeing (and verifying) your changes quickly, so we highly recommend using a TTL of 120 seconds or lower.
You will see a link to the DNS configuration screen on the “Customize” section of the account under the “Customize status page” tab. Here’s what it should look like if we’ve found you need to change something:
And here’s what it looks like when everything is appropriately configured: