OK, I'll keep this brief. Yes, the postal service delivers anonymous mail. Yes, you can make anonymous telephone calls using pay phones. But like all hastily construed analogies, they fail in the magnified specifics. The problem here is that the fragile remailers being built right now are operated by *individual users*, while these other services are parts of vast public infrastructures. Now, until anonymous servers become part of the vast public infrastructure (I'll give us all the benefit of the doubt on this one), operators will be *extremely* vulnerable to what goes through their remailers.
[stuff deleted] You fail to realize the obvious. Anyone who makes use of "vast public infrastructures" is also usually defenseless against the POWERS THAT BE, and fall victim to them abusing this power. Your snail mail can be intercepted/stolen and read at the command of the federales, any and all telephone calls can be intercepted/blocked/eavesdropped on. Sorry, but I'll take my chances with "fragile remailers", and the choice of use dictated by the positive reputations of both the remailer and the sender. Simple.