As the general intercourse between the two capitals now promised to be permanent, and travelling along the North Road increased rather than diminished, further general orders were published from time to time by royal proclamation. Two kinds of post were established during the reign of James the First, both being in operation together towards its close. They were known as the "_thorough post_," and "_the post for the packet_." The first, consisting of special messengers who rode "thorough post," that is, through the whole distance "with horse and guide," was established in 1603. The couriers were ordered to pay at the rate of "twopence-halfpenny the mile" for the hire of each horse, and to pay in advance. Further, they must not ride any horse more than one stage (or seven miles in summer, and six in winter), except "with the consent of the post of the stage at which they did not change." For the service of the second post, or "_the post for the packet_," every postmaster was bound to keep not less than two horses ready, "with furniture convenient," when on the receipt of a "packet" or parcel containing letters, from a previous stage, he was to send it on towards the next within a quarter of an hour of its receipt, entering the transaction in "a large and faire ledger paper book." As a further precaution, and in order to prevent the courier loitering on the road with any important despatch, each postmaster was required to endorse each single letter with the exact time of the messenger's arrival, just as we have seen in the case of the one found in the collection of Archbishop Parker's correspondence. For the purposes of this packet-post, we find it arranged that each postmaster should have ready "two bags of leather, at the least, well lined with baize or cotton, so as not to injure the letters." It also rested with the different postmasters to furnish the couriers with "_hornes_ to sound and blowe as oft as the post meets company, or at least four times in every mile."[11] Thus arose a custom which, under slightly different circumstances, was strictly observed in the days of mail-coaches.
It will be readily observed that in the arrangements of the packet-post there was nothing to prevent its being extensively used, except the important restrictions which the King put upon its use. During the reign of James nothing but the despatches of ambassadors were allowed to jostle the Government letters in the leather bags, "lined with baize or cotton," of "the post for the packet." It was not until Charles the First had succeeded his father, that this post came to be used, under certain conditions, by merchants and private persons.