1. Use the G Suite Toolbox to check your SPF record.
  2. Go to https://toolbox.googleapps.com/apps/checkmx/
  3. Enter your domain name.
  4. Click Run Checks!
  5. When the test finishes, click Effective SPF Address Ranges.
  6. Check the SPF results. The results should include:
    • _spf.google.com
    • _netblocks.google.com followed by several IP addresses
    • _netblocks2.google.com followed by several IP addresses
    • _netblocks3.google.com followed by several IP addresses