Does the oath I took upon myself, by placing my hand on the Qur'an, not to speak to any men except my maharim, include all men, even in daily transactions such as buying, selling, and delivery?

Oaths are based on intention. If there is no intention, then the oath refers to its cause. Otherwise, it refers to the literal meaning of the word. So, if you swore not to speak to a relative or a stranger, and you intended not to speak unnecessarily or in a way that leads to fitna (temptation/strife), or if you excluded vendors and delivery persons, then what you intended is valid. If there was no intention, the apparent reason is to prevent causes of fitna with men. This implies the permissibility of speaking with vendors, "Marsol," and "Careem" drivers. It is permissible to speak with them out of necessity, and it is better that this be with the knowledge and permission of your brother, to avoid doubt and dispute.