mailyoudaoicibaDictYouDict[mail 词源字典]
mail: English has two extant words mail. The one meaning ‘post’ [13] goes back via Old French to Old High German malha, which meant ‘bag, pouch’. That indeed was what the word originally denoted in English (and modern French malle is still used for a ‘bag’). It was not until the 17th century that a specific application to a ‘bag for carrying letters’ emerged, and this was followed in the next century by the ‘letters, etc so carried’. Mail ‘chain-armour’ [14] comes via Old French maille ‘mesh’ from Latin macula, which originally meant ‘spot, stain’ (hence English immaculate [15], etymologically ‘spotless’), but was transferred to the ‘holes in a net’, from their appearance of being spots or marks.

The word maquis, made familiar in English during World War II as a term for the French resistance forces, means literally ‘scrub, undergrowth’ in French. It was borrowed from Italian macchia, a descendant of Latin macula, whose literal sense ‘spot’ was applied metaphorically to ‘bushes dotted over a hillside’. English once had a third word mail, meaning ‘payment, tax’ [12].

It was borrowed from Old Norse mál ‘speech, agreement’. It now survives only in blackmail [16].
=> immaculate, maquis[mail etymology, mail origin, 英语词源]
mail (n.1)youdaoicibaDictYouDict
"post, letters," c. 1200, "a traveling bag," from Old French male "wallet, bag, bundle," from Frankish *malha or some other Germanic source, from Proto-Germanic *malho- (cognates: Old High German malaha "wallet, bag," Middle Dutch male "bag"), from PIE *molko- "skin, bag." Sense extension to "letters and parcels" (18c.) is via "bag full of letter" (1650s) or "person or vehicle who carries postal matter" (1650s). In 19c. England, mail was letters going abroad, while home dispatches were post. Sense of "personal batch of letters" is from 1844, originally American English.
mail (n.2)youdaoicibaDictYouDict
"metal ring armor," c. 1300, from Old French maille "link of mail, mesh of net," from Latin macula "mesh in a net," originally "spot, blemish," on notion that the gaps in a net or mesh looked like spots.
mail (v.)youdaoicibaDictYouDict
"send by post," 1828, American English, from mail (n.1). Related: Mailed; mailing; mailable. Mailing list attested from 1876.
mail (n.3)youdaoicibaDictYouDict
"rent, payment," from Old English mal (see blackmail (n.)).