邮政
yoú zhèng · HSK 7
postal service
📮 邮政 = 邮 mail/post + 政 administration: the mail-administration, i.e. the postal service
邮 carries the sense of post or mail, and 政 means government administration or affairs. Together 邮政 is literally the administration of the mail, which is exactly what a postal service is. The sound youzheng pairs you with the zheng also found in government words.
邮 — 由 (cause) + 阝 (city radical 邑)
邮 means 'post, mail.' The right-side 阝 derives from 邑 (city/settlement), pointing to relay stations along roads. The simplified form pairs this with 由, which here mainly carries the sound. Historically 邮 referred to the courier posts where messengers changed horses to relay official messages.