550 5.1.1: The mailbox does not exist
The receiving server looked for the mailbox and couldn't find it. The part before the @ is wrong, or the account has been closed.
Hard bounce The address is bad. Don't keep sending to it.
What the bounce message looks like
The wording changes from one provider to another. These are typical examples:
550 5.1.1 The email account that you tried to reach does not exist. Please try double-checking the recipient's email address for typos or unnecessary spaces. (Gmail)550 5.1.1 <[email protected]>: Recipient address rejected: User unknown in virtual mailbox tableCommon causes
- A typo in the name part, such as jhon@ instead of john@
- The person left the company and their mailbox was deleted
- An old or abandoned free email account that the provider closed
- An address copied from a website or list that was never real
How to fix it if you sent the email
- Check the spelling with the person, by phone or another channel.
- If the address is right, it no longer exists. Ask for a new one.
- If you send to a list, remove the address now. Repeated sends to dead addresses hurt your sender reputation.
If you manage the receiving or sending mail system
- Confirm the mailbox exists and is spelled the same way in your mail system.
- Check aliases and forwarding if the address used to work.
Free tool: paste the full bounce into the bounce message decoder to get a plain-English reading of every code in it.
Questions people ask
- What does 550 5.1.1 mean?
- The receiving server looked for the mailbox and couldn't find it. The part before the @ is wrong, or the account has been closed.
- Is 550 5.1.1 a hard or soft bounce?
- Hard bounce. The address is bad. Don't keep sending to it.
- Should I remove the address after a 5.1.1 bounce?
- Yes. Remove it from your list, or confirm a new address with the person first.