Below is an example of a new blackmail email that is appearing in Australian and New Zealanders inboxes. Blackmail emails are a popular way for criminals to make money. Previously the technique was to capture your attention by including information sourced through a known breach (in this case a previously used password) in the subject line. Now they are trying to trick you into believing your account has been hacked by sending you an email that seems to come from your own email account. This technique is known as ‘email spoofing’.
Email spoofing is when the sender of an email typically spam/forges/spoofs the email header "From" an address so the email being sent appears to have been sent from a legitimate email address that is not the spammers own address.
Reasons scammers do this:
While there is no fool-proof way to prevent either type of abuse to your email address, you could adopt some "best practices" when it comes to your email security:
The short answer is, not much. There are no definitive ways to prevent someone from harvesting your email address from the internet and using it for spam. Blocking your own email account may cause you more problems. If the spoofing is recurring and causing a lot of inconvenience, the best thing to do would be to delete the account and start over with a new email account (hence the recommendation regarding throw away email accounts). If you are getting relentlessly spammed, the attacks usually only last for a week or two, sometimes less. If it’s a one-off email like the example above, delete it and remain vigilant.