A great feature of eNotify is that you never have to worry about duplicate emails being sent. You can send an eNotice to as many of your lists as you want.
Whenever eNotify sends a message, it automatically filters out any duplicated email addresses, so you can identify multiple lists to target with a single email without worrying about whether there are people who are on both lists.
Additionally, you can re-import addresses into a list as often as you need to without filtering out the duplicates first.
The only time a person would ever get the same email twice is if they are on the list with two different email addresses (for example, John Smith is on the list with both firstname.lastname@example.org and email@example.com).
To add one or more lists to your eNotice, click the green "Add Lists" button in Compose eNotice and select all the lists you want to include in the mailing.