When a letter absolutely has to get to its location safely, you may use this sheild spell.
To start take a leaf from a rowan tree, or a needle from a pine and if possible encose the leaf or needle in the letter. If you cannot reassonably do so, rub the leaf or needle on the address. On the upper right hand corner of the front of the envelope where the stamp will go, draw a small shield with a bar sinister ( a bar going from the lower left to the upper right of the shiled) Cover it with a large brightly colored stamp (If you have a choice) In a strong voice, say to the letter.
By Mercury, Hermes, and Thoth, I charge
thee:
Horse and hattock, plane and truck:
Go, and go, and go
Nor stop till thou have reached the hand I
intend
So mote it be!