550 5.2.1: mailbox disabled or not accepting messages
The mailbox exists but has been disabled, so it will not accept mail.
Permanent failure (hard bounce)
What 550 5.2.1 means
Unlike 5.1.1, the account is known to the server. It has been suspended, deactivated or set not to receive mail, often after someone left an organisation.
Common causes
- An employee account that was deactivated
- A suspended account
- A mailbox set to reject all incoming messages
How to fix it
- Contact the recipient another way for a new address
- Remove the address from your list
What to do with the address
Treat it as invalid and 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 550 5.2.1 mean?
- The mailbox exists but has been disabled, so it will not accept mail. Unlike 5.1.1, the account is known to the server. It has been suspended, deactivated or set not to receive mail, often after someone left an organisation.
- Is 550 5.2.1 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 550 5.2.1?
- Treat it as invalid and remove it.