The email was sent to an address that doesn't exist

If you sent an email from your Yandex mailbox and received a non-delivery report with one of the following messages: “Bad destination mailbox address”, “Bad destination system address”, “Bad destination mailbox address syntax”, “DNS: no such domain”, “Invalid mailbox”, “Invalid recipient”, “Host or domain name not found”, “Mailbox unavailable”, “No such user here”, “The email account that you tried to reach does not exist”, “Unrouteable address”, “User not found”, “User unknown”, “401 4.5.4 Invalid arguments - possible version mismatch”, this means the email was sent to a non-existing address.

Make sure the recipient's address does not include extra punctuation marks, spaces, or quotation marks. Confirm the recipient's email address and resend the message.