Fix "550 5.7.1 relaying denied": The server refused to relay your message

Getting 550 5.7.1 relaying denied? It means the server refused to relay your message.

How to fix it

Authenticate to the server and send only from authorized domains.

Prevent it

• Authenticate with SPF, DKIM and DMARC.
• Use 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, 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.