I receive Mail Delivery Failure notices regularly for messages I did not send.

When you get mail from “MAILER-DAEMON” or “Mail Delivery Subsystem” with a subject like “Failed Delivery” or “Unable to Deliver” or “7 Rejected Attempts to Deliver Message” or similar, it means that an email you sent was undeliverable and has been “bounced” back to you.

These may be genuine messages, automatically generated by an error in sending on your email message, but they are often fake and that would indicate a serious problem with hackers and your email address.

If the message is genuine, the most likely reason for a failed delivery is that the email address you entered is invalid. Double-check the spelling of the address you entered or maybe the intended recipient has cancelled that email address.

There are two other main reasons why you might suddenly get a lot of email message delivery failure warnings:-

1. Your computer has been infected by malware and is being used by criminals to send out mass spam messages without your knowledge. Check your Sent Mail folder to see if this has happened.
2. A spammer is sending out messages that appear to be from your email address. This is called spoofing and is very common. An expert would see that the emails did not originate with you but most people receiving the messages will blame you and you may get some nasty replies from them.

Spammers send out vast numbers of mail messages, to random email addresses, and that typically means a high rate of failure and hence a lot of failure to deliver messages

If you receive a Mail Deliver Failure notice but have not sent the message, take these steps:-

1. Change your account password to something more secure. Use a strong password that is easy for you to remember but difficult for other people to guess. (see https://fightback.ninja/how-to-keep-your-passwords-safe/ for further information)
2. Run a Virus Scan and remove any malware. Make sure your anti-virus is up to date.

There is little you can do to stop hackers faking messages to look like they came from your address, except for deleting the email address so you don’t get any return failure messages.

Do enter your email address and click on the subscribe button on top right to keep up to date with new posts.