Why is SPF failing?

There are several reasons why SPF might fail for your emails. This list is non-exhaustive, but contains some common elements to start examining.

Incorrect SPF Configuration

If the SPF record in your domain's DNS is misconfigured (e.g., doesn't include your sending email server, or has a syntax error) or is missing entirely, the receiving server will not be able to verify that the email server was authorized to send mail for your domain, leading to a failure.

Email Forwarding

Some email providers or email forwarding services may modify the email's original "envelope from" address when forwarding your message, causing SPF to fail. This is why we recommend setting your SPF policy to "Soft Fail", so as long as the message passes DKIM validation, DMARC will pass and your message will still be delivered.

Too Many DNS Lookups

SPF records are limited to 10 DNS lookups. Exceeding this limit can cause validation to fail.