e-mail vs mail

e-mail and mail both are nouns.

Word	Noun	Adjective	Verb	Adverb
e-mail	Yes	No	Yes	No
mail	Yes	No	Yes	No

e-mail (noun)	mail (noun)
(computer science) a system of world-wide electronic communication in which a computer user can compose a message at one terminal that can be regenerated at the recipient's terminal when the recipient logs in	(Middle Ages) flexible armor made of interlinked metal rings
	a conveyance that transports the letters and packages that are conveyed by the postal system
	the system whereby messages are transmitted via the post office
	the bags of letters and packages that are transported by the postal service
	any particular collection of letters or packages that is delivered

e-mail (verb)	mail (verb)
communicate electronically on the computer	cause to be directed or transmitted to another place
	send via the postal service