Arriving from Venice to JFK mid week at 5:25pm, Delta.
Looking at Delta JFK to home in FLL, leaving at 7:50. Enough time??

If it makes a difference, I will be paying for the US to Italy round trip, and using Rewards for the domestic flights.

Thanks

Who knows? If your arrival flight is on time its comfortably enough time but if your arrival is delayed -- then nope. I don't fly Delta very often so don't know how it works for them but I have flown AA international/domestic all on one ticket and paid partly cash and partly miles. Isn't that a possibility on Delta to get everything on the same PNR?? Or can you have a revenue flight and reward flight combined on the same booking?? Unless someone else knows for sure, maybe call Delta and ask . . .

Is it enough time?

​​​​A: If everything goes according to plan, yes, you have enough time to go thru immigration, collect your luggage, go thru customs, then drop off your bags at Delta checkin.

if you can do this on one PNR then you have lots of excess time. If you cannot, at least be sure to check in online for for your domestic flight ahead of time.

if you are on separate tickets and your first flight is late then all bets are off.
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If you are not flying on one ticket (PNR), then if the flight into JFK is late or there is a backup at immigration or customs, you will be a no show for the domestic flight and lose your fare.