Sender Policy Framework (SPF) is an email authentication system that detects forged sender addresses while the email is being delivered. SPF is confined to detecting a forged sender claim in the email’s envelope, which is used when an email bounces.
You will either need to modify your existing SPF record or add a new one to set up SPF for Constant Contact. But before you can do that, log in to your DNS console and go to your desired domain. If you have an existing SPF record, modify it using the following value:
Include:spf.constantcontact.com
If you’ve previously used _spf.google.com -all, your new record will look like this:
v=spf1 include:_spf.google.com include:spf.constantcontact.com -all
If you don’t have an existing SPF record, add the following value to your DNS:
v=spf1 include:spf.constantcontact.com -all
After you have configured SPF, check and verify the records using EmailAuth’s free SPF checkup tool.