553 5.1.3: invalid recipient address syntax
The recipient address is not a valid email address format.
Permanent failure (hard bounce)
What 553 5.1.3 means
The server checked the address and found it malformed: stray spaces, missing @, two @ signs, illegal characters or a missing domain.
Common causes
- A typo or copy-paste error
- Spaces or commas inside the address
- A form field accepted an invalid address
How to fix it
- Correct the formatting
- Validate addresses at signup so malformed ones never reach your list
What to do with the address
Fix it if the intended address is obvious, otherwise remove it.
Check an address now with the free email checker, or look at a domain's mail setup with the email domain checker, MX lookup and SPF checker.
Related error codes
Frequently asked questions
- What does 553 5.1.3 mean?
- The recipient address is not a valid email address format. The server checked the address and found it malformed: stray spaces, missing @, two @ signs, illegal characters or a missing domain.
- Is 553 5.1.3 a hard bounce or a soft bounce?
- Permanent failure (hard bounce). The address will keep failing, so remove it.
- What should I do with the address after 553 5.1.3?
- Fix it if the intended address is obvious, otherwise remove it.