Cannot recover my API key

I have a site where I had generated an API key for the site using a certain admin account. I later had to restore the site from a backup before I installed Sucuri. I have just re-installed the plugin and when I try to generate the API key, it says there is already an existing key for my site/email combination and that a recovery e-mail with the key has been sent. However I never receive the email. Please help.

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