I receive the email if the Exclusion Script is not present.

But I'm not receiving the emails anymore as I think my Exclusion condition is wrong.

I have a DE with a primary key (Environment) that should match the variable, so I'm using the below condition in the Exclusion Script input box in the Triggered Send,

ROWCOUNT(LOOKUPROWS("MGO_Environment", "Environment", Environment)) > 0


Is something I'm missing?