Email provider
Rackspace SMTP Error Codes and Bounce Messages
Rackspace Email is a hosted mailbox product for businesses, with spam filtering, firewall and blocklist features and an unusually detailed public postmaster site.
- Codes on record
- 1
- Responses
- 1
Postmaster & documentation
SMTP 5501 response
A hard failure. The receiving server has refused the message for good and will not accept an unchanged retry without a change on the sending side. See SMTP 550 across every provider
Rackspace bounce questions
›Why is Rackspace bouncing my email?
Rackspace Email is a hosted mailbox product for businesses, with spam filtering, firewall and blocklist features and an unusually detailed public postmaster site. Match the exact wording of your bounce to one of the 1 responses on this page to find the specific reason and fix.
›How do I improve deliverability to Rackspace?
Authenticate with SPF, DKIM and DMARC, keep your sending IP and domain reputation clean, mail only engaged recipients, and honour unsubscribes. Rackspace also publishes postmaster guidance, linked on this page.
