If you run Gmail through Google Workspace on your own domain, a couple of DNS record types quietly determine whether your setup works smoothly: A records and rDNS (reverse DNS). Here's what each one actually does and where they can cause problems.
A quick DNS refresher
DNS is the system that translates human-friendly domain names into the numeric IP addresses computers use to connect to each other. When you send or receive email, several DNS record types work together: MX records point to the right mail servers, A records resolve hostnames to IP addresses, and (for outbound mail from your own server) PTR records confirm a sending IP matches a legitimate hostname.
Where A records fit into Google Workspace
For most Google Workspace users, Gmail's core functionality — sending and receiving mail through Google's own infrastructure — is handled primarily through MX records pointing to Google's mail servers, which Google provides during setup. A records become relevant in a few specific situations:
- Pointing your bare domain or a subdomain (like
mail.yourdomain.com) to a specific service address Google gives you during domain verification or service setup. - Supporting web access to a custom URL tied to Google Workspace apps.
- Configuring an outbound mail gateway if you route some outgoing mail through your own server before it reaches Google.
Because the exact IP addresses or hostnames Google asks you to use can change over time, always copy the current values directly from your Google Workspace admin console's setup wizard rather than relying on a value you saw somewhere else — using an outdated address is one of the most common causes of a broken setup.
Setting up an A record: the general process
- Log into wherever your domain's DNS is managed — for Avalon-hosted domains, that's your DNS zone editor in your hosting control panel.
- Find the option to add a new DNS record and choose type A.
- Enter the host or subdomain Google's setup instructions specify (often your root domain or a subdomain like "mail").
- Enter the exact IP address Google's admin console provides for that step.
- Set a reasonable TTL (an hour is typical) and save.
- Allow time for the change to propagate, then verify using a DNS lookup tool before assuming it hasn't worked.
Reverse DNS (rDNS) and Gmail
rDNS maps an IP address back to a hostname — the opposite of what an A record does — using a PTR record. For standard Google Workspace mailboxes, Google's own servers handle outbound delivery, so Google's rDNS setup is what matters, not anything on your end.
Where rDNS becomes your responsibility is if you send outbound mail through your own server (for example, as an SMTP relay or outbound gateway) before it reaches Google Workspace, or if you run mail infrastructure independently of Google. In that case, the PTR record for your sending IP needs to be set by whoever controls that IP address block — typically your hosting provider — and should resolve to a hostname that matches your mail server's own A record.
Common issues and fixes
- Domain verification fails. Confirm the exact record type and value from the current Google admin console instructions — these details are occasionally updated.
- Mail from a self-hosted relay lands in spam. Check that the relay's PTR record exists and matches its A record; contact your hosting provider if it needs to be set or corrected.
- Changes don't seem to take effect. DNS propagation can take anywhere from a few minutes up to about 48 hours; re-check after some time has passed before troubleshooting further.
- Conflicting records. An old A or CNAME record left over from a previous setup can silently override the one you just added — check for duplicates on the same hostname.
FAQ
Do I need to set up rDNS if I only use Gmail through Google Workspace normally? No — Google manages that for its own outbound servers. It only applies if you're relaying mail through your own server.
Where do I find the current A record values Google wants? Always pull them fresh from your Google Workspace admin console's domain setup section, since they can change.
Who do I contact to set a PTR record for my own mail server? Your hosting provider — for Avalon-hosted servers, that's our support team, since PTR records are tied to IP address ownership rather than your domain's DNS zone.
