decompile and label mail

ld_script.txt

@@ -133,7 +133,7 @@ SECTIONS {
         asm/pokemon_icon.o(.text);
         asm/script_movement.o(.text);
         asm/fldeff_cut.o(.text);
-        asm/mail_data.o(.text);
+        src/mail_data.o(.text);
         asm/map_name_popup.o(.text);
         asm/item_menu_icons.o(.text);
         asm/battle_anim_80D51AC.o(.text);