Answer:
Sends paper without using the post office.
What calls for help, when written in capital letters, is the same forwards, backwards and upside down?
It belongs to you, but other people use it more than you do. What is it?
It speaks without a tongue, and listens without ears.
There are four of these, but everyone's favorite seems to be spades.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.