Web vs. email vulnerability

I'm doing an assessment for a project, and I've come
up with an interesting question I'd like some feedback
on. Which is more vulneable to hacker attacks,
hijacking a website or hijacking incoming email?

What I mean by hijacking a website is a hacker
changing the DNS resolution for a domain so that all
traffic is routed to a site he controls instead of the
authentic site. Let's assume that everything goes over
HTTP and not HTTPS (where things get much tougher for
the hacker).

By hijacking email, I mean the hacker modifying things
so that all email coming to a specific email account
is routed to him instead. 

In neither case does the hacker have any special
access, he's just a random hacker, he doesn't work for
an ISP or domain registrar.

So my question is: is either of these two cases more
vulnerable than the other? I contend that both cases
are equally vulnerable since they both rely on the
fidelity of DNS records. Someone who can play games
with the DNS records can easily launch either of these
attacks. Now having said that, my gut feeling is that
I'm wrong. I'm looking for other people's ideas to
either tell me I'm right, or explain why I'm wrong.

Thanks a lot for your help.