Multiple IP Lockout Notification Emails

Hello –

I started getting a lot of lockout emails for this one fairly new site: imatteryoumatter.com.
I turned on the “Hide Backend” Feature yesterday and I’m still getting them, especially from a couple of the same IP addresses.

I had a little difficulty at first with the whole site producing an error and 404s on all pages, but got everything working again by clearing cache, resetting permalinks, and reinstalling the plug-in. (I don’t know if any of that is relevant.)

1. Should I be worried.
2. Is there something more I should do to protect the site and reduce these notices?

I’ve been using the plug-in on many sites for a while now, but try to stick with the basic settings as much as possible to avoid problems with themes, etc. I’ll admit I’m not familiar with a lot of the technical language and I’m learning as I go.

Thanks for any assistance,
Katie

I’ve pasted one of the emails below:

“Dear Site Admin,

A host, 155.133.82.62, has been locked out of the WordPress site at http://imatteryoumatter.com due to too many bad login attempts.

The host has been locked out permanently .

*This email was generated automatically by iThemes Security. To change your email preferences please visit the plugin settings.”