mails / males are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
mails: (noun) the bags of letters and packages that are transported by the postal service. (noun) the system whereby messages are transmitted via the post office. (noun) a conveyance that transports the letters and packages that are conveyed by the postal system. (noun) any particular collection of letters or packages that is delivered. (verb) send via the postal service. (verb) cause to be directed or transmitted to another place.
males: (noun) an animal that produces gametes (spermatozoa) that can fertilize female gametes (ova). (noun) a person who belongs to the sex that cannot have babies. (noun) the capital of Maldives in the center of the islands.
mails: m·EY·l·z
males: m·EY·l·z
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)