Error Email – Nothing in Table

First off, this plug-in is pretty good. But I have an issue and also a suggestion.

The issue is that I have received an error 404 email. The error shows the page /blog which we don’t have on our site, so I would like to go into the table [404 Errors], select the entry and tell it to go elsewhere. However, I can’t do that because this isn’t captured in the table of available URLs to manage? – If its not in the table, then how have I received an email? *confused*

Also, the majority of error emails I receive show referral page as: na.

My suggestion.
For the ability to be able to create our own redirect entry. So in my example above, I could enter a new line for /blog to redirect to /gallary etc without using archaic moves like htaccess editing.