Invalid Email Account
If you get error 550 (or 554, depending on the recipient’s email server), it means that the email address you are sending the message to does not exist.
Example of messages associated with this error:
550 [email] User unknown
550 Sorry, no mailbox here by that name. (#5.1.1)
550 Requested action not taken: mailbox unavailable
550 5.1.1 [email] is not a valid mailbox
550 No Such User Here
550 Invalid recipient
[email] (user not found)
5.1.0 – Unknown address error 550-‘MAILBOX NOT FOUND’
550-5.1.1 The email account that you tried to reach does not exist.
550 5.1.1 [e-mail]: Recipient address rejected: User unknown in relay recipient table
554 delivery error: This user doesn’t have a [name of the service] account
554 delivery error: Sorry your message to [email] cannot be delivered. This account has been disabled or discontinued
550 #5.1.0 Address rejected [email]
A message that is related to the same problem we are describing is this one, where the recipient’s host (i.e., email server) doesn’t exist:
Sorry, I couldn’t find any host named [host]. (#5.1.2)
If you got the email address from a real person, most likely there is a typo somewhere. Double check the email address you typed. If you obtained the address by phone, you may have misheard the name or a letter and ended up writing down the wrong email address.
However, if you obtained the recipient’s email from a website, from a magazine, an advertisement, etcetera, and you double-checked it to make sure there is no typo, this means that the email simply doesn’t exist. We know how frustrating this may be, but there is nothing we can do about it!