It's delivered regularly (4)
I believe the answer is:
(Other definitions for mail that I've seen before include "Armour of interlinked metal rings" , "protective cover" , "Dispatch - armour" , "letter?" , "Form of armour; post" .)
I believe the answer is:
(Other definitions for mail that I've seen before include "Armour of interlinked metal rings" , "protective cover" , "Dispatch - armour" , "letter?" , "Form of armour; post" .)