The easiest way to do this is to create a query and generate a group from those results.
To create the query:
  1. Go to Data Management -> Query
  2. Create a new query and save
  3. Select Address in the first drop down
  4. You can then choose your secondary criteria such as city, congressional district, county, zip (note! if you are querying for a specific district you need to also have a clause for the state, e.g. STATE/PROV is TX AND DISTRICT is 34)
  5. Save the query and "use" the results
  6. Create a new group or assign to an existing group.
  7. If you create a new group, this can be updated daily/weekly etc. and stay current for future emails as well.
Note: If you have the Advocacy module there are several built-in groups that you can use for targeting. Please refer to this solution for more information.