When you want to guide traffic from a subdomain, e.g. www.example.com or mail.example.com to another server, you can use CNAME records. You can also use CNAME records to reset your administrator password and verify domain ownership. Note that creating a CNAME record does not disrupt your current mailflow or affect other services.
You can modify CNAME records using the administration tools available from your domain host, not the Google Admin console. The basic steps below are applicable to all domain hosts. The exact steps for doing so are slightly different for each host. See CNAME records for specific domain providers. You may need to Identify your domain host first. See What should I tell my domain host? for advice.
To configure CNAME records for a domain:
- Sign in to the domain host's administrative console for your domain.
- Locate the page on which you can update the domain DNS records.
The page might be called something like DNS Management, Name Server Management, or Advanced Settings.
- Locate the CNAME records for your domain. You may have one or more CNAME records resembling:
Name / Host / Alias Time to Live (TTL) Record Type Value / Answer / Destination www 86400 CNAME yourdomain.com. or @ mail 86400 CNAME yourdomain.com. or @ - Optionally, reduce the Time to Live (TTL) to 300 seconds for every CNAME record. This tells name servers across the internet to check every 300 seconds (or five minutes) whether you updated these DNS records. This allows you to apply changes to your DNS records much more quickly. Also, if necessary, you can revert any DNS record changes a lot quicker when you’ve set a low TTL.
Any DNS record change will apply only after the initial TTL of that record expires. For example, a value of 86400 seconds = 1440 minutes = 24 hours before any update will be applied. This also means that you need to wait 24 hours after the TTL of a DNS record is updated once you change it to 300 from 86400.
- Update the existing CNAME records to include the value / answer / destination of the desired CNAME record values. Create new CNAME records if necessary. Note: For reseller applicants, use instructions for subdomain verification.
- Save your changes and wait until they take effect.
Be aware it may take up to 72 hours before changes are propagated, depending on the TTL that was configured for your CNAME records.
- CNAME Label / Host needs to be appended with the subdomain. (Example: JLKDER712AFP.subdomain)
- CNAME Destination / Target is copied as is.
If you have difficulty, first try to troubleshoot CNAME records. Then contact your domain host for assistance.
