As far as Mr Jack's comment about copyright, that is a bit bizarre under US law.
That is, the words are copyrighted by the author, but the physical item is property of the recipient. That is, if you were to write me a physical letter, you would own the copyright on the words you wrote, but I could physically show the letter to anybody I wanted.
How this applies to email where there is no physical item, I'm not quite sure.
Well, yes. You can show anyone you like a book, but the copyright on the book is owned by the author, or publisher. Same with e-mail, and physical letters, you could show someone your copy, but you couldn't photocopy it, or copy the words somewhere else.
With e-mail, legal precedent has it that sending someone else a copy, or posting the contents, or printing it out and giving it to other people is copyright violation.