Now, everyone knows that birds make great couriers, and the practice of using homing pigeons to carry messages is as old as the ancient Persians. Post birds were also used by the Ancient Greeks, French soldiers, and even now by news agencies wanting to report on yacht racing. 

Of all mail-carrying birds, Owls may be some of the best, as evidenced by the world of Harry Potter. Owls in the wizarding world seem to have some sixth sense, and are able to find the letter's recipient even if they are on holiday, on the run, or are being addressed under a pseudonym.

If you lack your own owl, and your neighbourhood does not run an Owlery, then never fear! A small paper owl, some string and a quick charm will do the trick.

THE LETTER & THE OWL

You are going to want to arrange your letters and invitations before conducting the spell. So first gather your quills and parchment, and get writing. Then seal that letter in the envelope with some kind of stamp or wax, as you do not want it to fall out mid-flight. Next, draw up a paper owl, and attach it with a string to that letter. 

CASTING THE SPELL

Next comes the enchantment. We are going to use transfiguration here, and the spell we are using is called the Avifors Spell, from the Standard Book of Spells, Grade 2. A few quick tips first:

Now, the Avifors spell will turn a target object into a bird, or a flock of birds. Use your Avifors spell to turn that paper owl into a real, hooting, postal Owl. Aim your wand at the paper owl, recite the incantation as shown in the Standard Book of Spells, Grade 2, and watch as it transforms. Just be sure to give it the directions to the letter's recipient, as paper owls are much less reliable than the real thing.