1. Click Queries in the menu bar
2. Click Manage Queries
3. Select a category that you want to store this query in (Example: Base)
4. Click New Query under Tasks
5. Name the query Accounts with an Email Address
6. For Starting Query choose Category: Base and Query: All Constituents
7. For Data Return Type choose Accounts
8. Under Criteria Options select "Match all criteria"
9. Under Browse Fields select Account from the drop down menu
10. Click Email Address
11. Check Field Has Any Value
12. Click Save and Preview

This query will contain all accounts that have an email address on any of their active personas.