Here is what constitutes a "valid" email addresses:
  1. Accept Email equals true.
  2. Email Status not equal to Bad (Hard Bounce).
  3. Email is not blank
  4. System Active Status not equal to Removed.
  5. Deceased equals False
We can Create a Query to identify the constituents that have a valid email. In query builder, create the following clauses:

Field Type: Email
Field: Accept Email
Clause: equals true
AND
Field Type: Email
Field: Email Status
Clause: not equal to Bad (Hard Bounce)
AND
Field Type: Email
Field: Email
Clause: is not blank
AND
Field Type: System
Field: Active Status
Clause: not equal to Removed
AND
(Optionally add this filter if you use the deceased field)
Field Type: Biographical Information
Field: Deceased
Clause: equals false

If you only want to see valid email addresses in a specific group, then you'll want to Add a Group Clause, but if you want to see all valid emails in your database, then you can leave this part out.