The task is sending a letter, not a parcel. You buy the stamps (from the post office, another shop with opening hours you prefer, or online), sick one on the e

The task is sending a letter, not a parcel. You buy the stamps (from the post office, another shop with opening hours you prefer, or online), sick one on the envelope and put it in a mailbox. Overcomplicating everything so you can grumble on the internet isn't required.