I had to pause a Smart Blast to make an edit in the template. Can I re-enable the Smart Blast to finish the send?
Short answer - Yes!
Re-enabling a paused smart blast will not create duplicate sends, it will finish out the original segment as intended. Extra time will need to be added to the send schedule; this gives Smart Blast a second chance to reach the users skipped while the send was paused.
My Smart Blast has finished sending, can I re-schedule the template and reach these users again?
Short answer - No!
To re-use the content in a completed Smart Blast you must clone the template and set up a new blast.
When you build a Smart Blast, all attributes of your Smart Blast are tied to an ID we call the 'Campaign Parameter ID'. All versions (edits) of your email are tied to the Campaign Parameter ID, and the ID never changes.
When Cortex queues up users for a Smart Blast it checks "has this Campaign Parameter ID sent to this user?" If yes, the template will not send. This ensures that users do not receive duplicate sends from a smart blast.
Cloning a Cortex email generates a new Campaign Parameter ID, so this allows us to re-use an older message, sending it a second time to the same list of users.