These are soft bounces caused by an automatic response from the recipient, for example “Out Of Office” messages. When your mail fails to arrive, you may wonder where to send it. If you have received an email that bounced, you can contact the postmaster for help. A bounced email is an indication that the address was closed or has been moved. If it’s been moved, you need to contact the postmaster and ask for assistance.
In some cases, error reports may be received even if the user has not sent any messages. The number of mail delivery subsystem error reports received may total in the thousands. A single misplaced letter can be enough to cause a failed delivery. If the message continues to be bounced back to you, you might want to verify that the email address you’re trying to send it to hasn’t been closed or moved. Messages from mail delivery subsystem are not spam messages.
They are error messages sent by the mail server at which you sent s email to someone. Usually it means the mail id does not exist or the persons ‘s mail box is full and can not accept any more messages until some space is created in their mailbox. When an email fails to deliver, the Mailer Daemon will report it as a failed delivery. The reason for this failure will be listed in the email’s header. A message that bounces can be either a valid or invalid email address. Neither of these reasons can prevent an email from being delivered.
The Mailer Daemon will report this to the sender if it finds the address to be invalid. However, in many cases, a single letter can cause a message to be delivered. When some of the spam messages cannot be delivered, the error report goes to the “from” address of the spam email. If a user receives several such error message a day, it may be a sign that the email account has been hacked.
Another common reason for email delivery failure is an invalid email address. The Mailer Daemon will check your email address, but an incorrect address can still result in a bounced message. Even a misplaced letter can cause your email to be returned.
Or the host server may have been configured to reject your email. The most common cause of this is an error in the settings of your email software. The best thing to do if an account has been hacked is to change the password. In extreme cases where it does not stop, the email account may have to be closed and changed. Check that the person gave you the correct email address. When you scan your computer for malware, make sure you’re disconnected from the internet, and change all of your account passwords when you’re done.