I've received a couple of blackmail emails recently, seemingly from different people but with the same format, each claiming that they've got access to my email account & also have evidence of me accessing "intimate" websites. Now, given that I'm not prone to visiting such sites, I wasn't overly concerned the first time, although I did Google to confirm that it is possible to send an email that makes it look like it's come from a different address.
What concerns me now is that I've had an email which includes an all lower case version of my password. I use a mix of upper/lower cases so their version isn't actually what my current password is but it is a version that I occasionally use for other websites, which is how they claim to have got it. They also claim to have put software on my operating system & claim to have set it up so they're notified of any changes to my password.
Obviously I won't be sending them any bitcoins... What can/should I do in response? Ignore it & delete the emails as they come in? Assume they won't know & update all the passwords I can think of that might use the same one? Go more drastic & get a new email address? I've been thinking I wish I had a different email for a while - it's still the same one I had as a teen when I thought I was being clever... 
I feel like changing it because of these people would be a version of letting them win but then again, if it stopped the emails I'd consider that a win for me!