What's Causing This Error
This error occurs when the sender's domain SPF validation fails while sending an email, and therefore the recipient does not accept the email. The most common issues causing this error are:
- SFP record unavailable.
- SFP syntax errors.
- Multiple SFP records for a single domain.
Solution - Here's How To Resolve It
To troubleshoot this issue, follow these steps:
- Ensure that an SFP record is available for the domain.
- Ensure that the SFP record follows the valid syntax.
- Ensure that the domain only has one SFP record.