Place for pen pals? (3)
I believe the answer is:
sty
'place for pen pals?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sty that I've seen before include "Pig-pen and infection on the eyelid" , "Porcine pen" , "See 15" , "Pig-pen and eye infection" , "Piggery" .)