If you have problems with SPF, consider the following:
SPF is Not Set Up
You must set up SPF according to the instructions furnished by your DNS provider. If you have questions, issues, or cannot find the instructions, reach out to your provider for assistance.
SPF Configuration Error
Check that you added and configured your SPF record correctly, based on your DNS provider's instructions.
Review specific syntax issues that your DNS provider might require you to enforce. If there is any confusion, contact your DNS provider for clarification.
Compare the provider's samples and instructions with your DNS records to see if you might have changed the syntax of the record incorrectly.
Make sure that:
- Your SPF record starts with the SPF version number (e.g., v=spf1)
- Your SPF record ends in ~all
- If a VPS (Virtual Private Server) is present, your record must include:
- a
- mx
- Your IP address
- If a VPS is not present, your record must include:
- a
- mx
- Your IP address
- a record and MX record for the host domain of any shared servers
- If you have other services, like office mail servers or domains acting as aliases to this domain:
- include their IP addresses
Email Forwarding
Forwarding an email will break SPF. If you are getting a lot of emails that seem to be failing SPF for forwarding, consider setting up DKIM for this service as well. Forwarding does not break DKIM. Having both SPF and DKIM provides more redundancy and will reduce these failures.
Domain Lookups
Your SPF record might be looking up too many domains. There is a limit of 10 lookups per domain. If this limit is reached, SPF will fail.
Your service might give you a domain to use for SPF and that domain might include multiple subdomains. Depending on how many services you have set up for SPF and how many lookups those services are doing, you might hit the limit of 10 lookups – after which SPF will fail.
Look at your SPF records and see if there is a way to reduce the number of lookups.