My KDF captains have brigs bursting with Prisoners and only a handful of mission to sell/execute them. While my Fed captains never have prisoners to "transfer". Bingo bango, I mailed some prisoners to my Fed captain... but noooo... The KDF prisoners can't be used in the Fed mission. Which I suppose makes some sense as they are Federation members held prisoner by the KDF. But I found it curious that the system allowed my Fed captain to accept these prisoners. They are useless to my Fed captain.
Similarly, my Fed captains can't get enough contraband which my KDF captains have stacks of. This is easy to mail across.
Is there some repeatable way to get Fed usable prisoners? How about Contraband? (Yes, I know all about the Confiscate from Crew mission--anything else?)
On a side note... are these two working as intended? Was it planned that KDF would be able to get Contraband easily and thus sell it to the Feds?
You can also find "Investigate reports of trafficking in contraband" missions that last 20 hours if you search around sectors. As well as yielding contraband, they also reward a nice amount of diplomatic CXP.
As for prisoners, the best fed source of them is the repeatable at the end of the 4028 chain. I think I got 3-4 regular prisoners and a blue Dominion prisoner from it recently. That blue prisoner is especially nice, since it gives a good boost on any prisoner related missions - you're usually stuck with whites on those.
inspect civ freighter, confiscate contraband from crew, trade gpl for contraband, and strike fugitive network (4028 repeatable) are the main sources of contraband for fed, and you could also do stuff like illegal gambling, investigate reports of trafficking, track X fleet movements, debrief prisoner, etc if you really need more.
or you could always just mail them from a kdf toon.