That's normal behavior, because you can have a site that's subscription access only which means when a subscription lapses the user is auto-blocked to prevent access. In that scenario sending an email to a blocked user makes sense. In your case you'll want to condition those users out. One way you can do this is by adding the below condition under the Condition tab.

First condition: This condition
Date A, Field A or Value A: Constant Value or String (CB substitutions can be used)
Value A: [block]
Date B, Field B or Value B: Constant Value or String (CB substitutions can be used)
Value B: 0
Condition 1 (> for Dates): A = B (Value A is equal to Value B )