Southeast has tried scheduled service out of ATL and CLT to CUN, FLL, and MCO. They were also operating a shuttle type service out of an airport in VA. They have mainly been a charter airline doing work for FunJet Vacations and others. When they were flying scheduled service out of ATL, they even had a sign at the airport for which terminal they had their check in at. I even saw an ad for them on t.v. I know they have a website, http://www.jetsoutheast.com
but am unsure if it still works.