This is chain mail (or other mail armour), not post.

• 5.046 All in mail never clinking.
• 12.014 could dimly be seen coats of mail, helms and axes, swords and spears hanging;
• 12.096 coats of mail gilded
• 13.035 Now the dwarves took down mail
• 13.037 With that he put on Bilbo a small coat of mail,
• 13.042 Their glittering mail they had covered again
• 16.026 (which he still wore over his mail)
• 17.028 You have mail upon you,
• 17.031 in a hauberk of steel mail
• 19.039 His coat of mail was arranged on a stand