I want to copy a number of subscribers from one subscriberslist to another without deleting the data of these subscribers from the original list. How do I do that?

I am currently looking for a way to have a single subscriber entry, but then select which lists they are on. It seems like a basic feature that Constant Contact and every other newsletter system out there has, but it seems that RSMail does not yet have that feature.
There should be a table that is the master subscriber table with fields that show what lists that subscriber is associated with. A typical subscriber would likely be subscribed to multiple lists.
Without the ability to have different subscriber lists, you cannot achieve segmentation of your email marketing campaign recipients.

I entered a ticket with RSJoomla support and they conveyed that what I am looking for is not in the RSMail component now and they don't plan on putting it into the product. I will keep trying to use the product, but I also may just switch to AcyMailing Enterprise. I am currently unable to get the DKIM component in RSForms Pro with the Mailer plugin to work. That means that the DKIM component in RSMail is not yet working either.