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

If you have sent a message to a Yandex address and received a non-delivery report that states the following: “Bad recipient address syntax”, “Bad address mailbox syntax”, “No correct recipients”, “No such user”, “Recipient address rejected: need fully-qualified address”, this means that the message has been sent to an address that does not exist.

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.