[yeuking]

I have received this email from unknown sender. Should I ignore this email? Since he mention my really old password on email.

[GraemeL]

Ignore it. They got the password from a data breach somewhere.

Change the password on any other site that you use that password for.

Using a password manager makes it much easier to use unique, complex passwords for each site you have a login for.

[yeuking]

Thanks, anyway I have changed all the password since that time.