Merge multiple lists we can send the newsletters.
but problem is that the various groups are constantly introduced new titles, but they will not be automatically consolidated group.
So every time the combined group will be created. As for inorganic unmanageable after a while.
If you delete a group, the campaign will also be deleted so that the statistics, which in turn should.
1. the group setting, do not subscribe to other category posts the title, but also because unsubscribe. but it would be necessary to enter into the other category titles
2. If you delete a group, the Campaign and the associated statistics should not cleared