Franked mails are the mails send by franking machines. Stamped mails are way different from franked mails. If you sent a franked mail, the information about it will be added in your franking license if you rent or buy a franking machine from EPS.
You can use the Royal mail website for downloading a copy of the license. To send a franked mail, mail must be sorted by class and then it should be carried into a pouch and that pouch should be deposited into a business post box. You can make it a part of your normal business collection and have it collected or you can transfer it to your convenient mail centre or post office. You have to post your franked mail before the last collection time on the date shown.
You can send the mail by a first class mail pouch which is filled with clear orientated letters and sorted into different pouches for every format. You can send the mail by a first class traditional style pouch too. You can also use a second class traditional pouch to send the mail.
Local mail centre will provide trays, containers and pouches without charging any fees. You can contact them and collect it.