There are various options that you can opt for to send your priority mail. The same can be taken from any of the commercial stationery suppliers who deal with the envelopes or your post office that is near your house or located in the vicinity. The first-class mails that weigh above thirteen ounces are termed priority mails. If you are opting to use an envelope that you make by yourself, you can mark the envelope with the words ‘Priority Mail’ on the top of the envelope. The USPS provides priority mail packaging. You should choose to use them while sending the priority mails.