This handy feature is available from your Distribution tab.
Step 1: Go to Distribution, then Sent.
Step 2: Select the message you would like to pull the recipient list from.
Step 3: Navigate to View Message and select Copy Recipients.
This presents two options…
Option 1: Send Email
This allows you to compose a new email with the same group of recipients.
Choosing to send it as an email initiates a new draft email and provides the option to edit your recipient list.
Option 2: Save As A List
Opting to save it as a new list will allow you to rename your distribution list for future use.