No, you do not have my permission without a warrant

Who may read my private correspondence without a warrant?

Nobody; except me, the addressee, and my mother.  And my mother is dead.

UPDATE: (9/3/16)  I'm not The Only One who objects to this governmental invasion of my personal privacy without warrant or notice.)  

the Patrick Henry Society.

FBI Director James Comey .... wants to assure us that there's nothing to see here, we should just move on.
In the meantime, he wants to invade our private conversations because he can.  
Not because he should, not because we agree to his invasion of our privacy, but because he can;
if he can break the code; since when must we count on Iphone security codes rather than the Constitution to protect our right to privacy?

He wants to have an "adult conversation"?  Then he should put on his Big Boy Pants and understand that just because that's what he WANTS, that doesn't necessarily mean he can HAVE IT!

Because Constitution.  Because WARRANT.  Because SEARCH AND SEIZURE.

Say I live on Rural Route 12, and my mailbox is a big tin thing with a red flag on the side.  If that flag is up, the mailman knows to stop and collect from my outbasket.  That's okay, that's his job and he's not reading my mail.

When you take my letters out of my mailbox, pal, you better have gone before a judge and presented a valid reason to do so.  And that judge needs to give you a warrant.  One for me, one for my neighbor, one for the stranger who just moved in down the road.  Specific cases ... not some broadly imprecise, the-whole-world "I need to read everybody's mail, 'cause one of them might be part of a conspiracy".

It's my mail, and you can't have it.  Consider that my final offer, except for the shotgun I use to keep the fox out of the henhouse.  And you're looking might red just now, pal.

"The conversation we've been trying to have about this has dipped below public consciousness now, and that's fine," Comey said at a symposium organized by Symantec, a technology company. "Because what we want to do is collect information this year so that next year we can have an adult conversation in this country." 

 The American people, he said, have a reasonable expectation of privacy in private spaces — including houses, cars and electronic devices. But that right is not absolute when law enforcement has probable cause to believe that there's evidence of a crime in one of those places, including a laptop or smartphone.

"With good reason, the people of the United States — through judges and law enforcement — can invade our private spaces," Comey said, adding that that "bargain" has been at the center of the country since its inception.

PS: I expect the same rights to Privacy as Hillary Clinton ... except more, because I'm a private citizen and not a public figure.  So go publish ALL of her private emails, why don't you?