Issue: Email addresses are rewritten as firstname.lastname@example.org instead of user@your_domain.com.
Resolution: This is a problem with your domain's DNS records. Your domain should not be used as a CNAME record. Only subdomains should be CNAME records. When DNS records are set up properly, a CNAME lookup for 'your_domain.com' will not produce any results.
For instance, if you own the domain example.com and you use this domain as a CNAME record and point it to ghs.googlehosted.com, your user's email address will be rewritten as email@example.com. In this case, a CNAME look up for example.com will produce the following result:
Non-authoritative answer: example.com canonical name = ghs.googlehosted.com
If you get 'ghs.googlehosted.com' as the result for your CNAME lookup, please reset your DNS settings to ensure that you are not using your domain name as a CNAME record.
Please note that G Suite utilizes CNAME records only in the case of verifying domain ownership or activating custom URLs for the various G Suite services. When a custom URL is set up properly, a CNAME lookup for the custom URL will produce 'ghs.googlehosted.com' as the result. For example, if you create a custom URL 'mail.example.com' for your G Suite email service, a CNAME lookup for mail.example.com will produce 'ghs.googlehosted.com' as the result as shown below:
Non-authoritative answer: mail.example.com canonical name = ghs.googlehosted.com
Note: If you purchased your domain name while signing up for G Suite, you won't need to create CNAME records. This is auto-configured for you when you select a custom URL in the Google Admin console.