Below are a number of fanmail addresses you can use to contact Dominic! :)

Dominic Monaghan
c/o Grass Skirt Productions
680 Iwilei Road
Honolulu, HI 96817

Dominic Monaghan c/o PFD
Drury House
34-43 Russell Street
London WC2B 5HA
England

Dominic Monaghan c/o Lost
Touchstone Television
500 South Buena Vista
Production Building #343
Burbank, CA 91521
USA