I have tried offering hatchlings red-backed salamanders and other small species, though unsuccessfully. The hatchling I kept would only eat worms after they had dried out. The snake I fed was practically scared of the salamanders - I don't think they like anything slimy.
One thing about feeding 'phibs to snakes - some species of salamanders are toxic, including baby spotteds (although most are too large anyway). Also, cold-blooded prey are much less nutritious than rodents - if your snake accepts them, you will have to feed it much more often.
You may want to try brumating your snake. My baby eastern would not eat anything until after hibernation. Easterns can survive much lower hibernating temps than you think. I began brumating mine in mid-November.
Best of luck,
Pinstripe