First, let me say that you still are not taking rdfield's advice from Re: Database not storing data.

I'm only going to talk about the following line of code:
$dbm{'$notverified'}= join "::",@unverified_emails;
I leave it up to you to learn from this and rewrite the rest of your script.

This joins the elements of @unverified_emails into a string seperated by double colons. It stores that string in $dbm{'$notverified'}. Let me rephrase that, you are storing the newly created string in the database file in a key called $notverified. I should stress that the key name is literally $notverified and not a variable referring to another key name. I reiterate; '$notverified' is a literal string. Why? Because it is wrapped in single quotes. Single quotes do not interpolate variables like double quotes do. So every time that this script is run, you will be overwriting the old data in $dbm{'$notverified'} with the new data.