Fix "550 5.7.1 (SPF)": The message was rejected because SPF failed

Bouncing with 550 5.7.1 (SPF)? It means the message was rejected because SPF failed.

How to fix it

Add the sending source to SPF and align it with your From domain.

Prevent it

• Authenticate with SPF, DKIM and DMARC.
• Send from a dedicated IP.
• Keep bounce and complaint rates low.

How Rainmail helps

Rainmail sends from your own domain on a dedicated, isolated IP with SPF, DKIM, DMARC, reverse-DNS and managed warm-up handled for you, plus a REST API and an AI watching deliverability — and it welcomes senders SES, SendGrid and Mailchimp reject, from $8. Run the free checker or see plans.