Charging for email is an inevitability. The corporate marketing machines will spin full speed, the media will eat it up and spoonfeed it to the masses as a "good thing" and "such a small price to pay to fight the evil spammers". People will buy into it using comparisons of paying for other forms of communication (fax, phone, snailmail) as their acceptance that this is "just the way things are".

Of course, the ongoing costs to fight the spammers will require this postage to go up and up and up....
...and it will utlimately be as futile as the war against snailmail spammers.