Based on your screenshot, the email address needs to be a list (because you are returning different values for each email address). So, as JJ stated, you will need a differnent module, but based on the email address.
Create the Email Address list (with a Top Level Item called All Email Addresses) based off the first occurrence (function is ISFIRSTOCCURRENCE() ) of the email address from the transaction module.
In the Transaction module, create a line item called Count and hardcode it to 1 (formatted as a number). Create another line item named Sent Count (formatted by the Email Address list) with the formula: if Status="Sent" then email adress else blank.
In the summary module, your list or Applies To should be Email Address with one line item called Summary (formatted as Number). The formula should be Transaction Module.Count[sum:Transaction Module.Sent Count]. Create a second line item, called Valid? (formatted as boolean) with the formula: Summary<>0. Filter on the Valid? line item in a view.