simple news emails

I could use some help with simple news. I switched from acajoomla to drupal simple news. The do not work the same. I have been trying to find information about simplenews emails but I am could not.
I need to import several different email lists that have over 1000 names. I can only send out 750 per hour. How do I set the limit per hour?
How do I import different email lists and be able to select specific lists per newsletters?
When I import the different lists, I do not see where I can select the specific list for that newsletter. Some lists are b2b and some are b2c.