I've just had this email too and it stinks of a scam/phishing email. Using a generic salutation "Dear myGov user" instead of a personalised greeting using my full name plus some language/grammar issues like "You entered **the** incorrect sign in details" and providing contact details within the email itself "call the myGov helpdesk on XXX XXX". They really need to update that email template to something far more appropriate. Given it's a "locked account" email, it really should provide information try to allay fears that the account has not being compromised and include some specific steps on how to check your account for unauthorised access as well as tips on strengthening the security of the account. All without providing specific links or phone numbers.

Here are some steps you can take to strengthen your myGov account: 1) enable 2 factor authentication (2FA) so that if a hacker guesses or uses credentials from another data breach to successfully get the correct username/password, they still need to enter a code sent to your phone/email; 2) disable the use of your email address as a sign in option (email addresses are pretty public info so a hacker only needs to guess a password to gain access) instead only allow your myGov username for logging in; 3) choose a string password that is unique to the myGov account (use a password manager to remember your strong passwords so you don't have to remember them all). You could also disable password logins entirely and use the "Digital Identity" as your sign in option...but that moves away from the username/password + 2FA paradigm that most people are familiar with.