Do you think Email is a commodity, but SMTP service is not? If you think it is, have you planned for what happens when your primary mail service, including SMTP goes down?
I doubt it, because most people do not even realize how email is broken down into parts that only a small bit are the responsibility of your own IT team.
When you have in house email, everything, except the ISP providing your bandwidth, is your own world. You break it, you fix it. You do, or do not, plan for business interruptions. Maybe you have a secondary ISP, even if it is some lousy DSL line, you have something, anything. You do, right?
What about when you get to cloud apps and you have a LDAP in one service or server, your app on one server, your mail transport on another, mobile site on another, your company website on yet another one.
When any of those parts fail, most of the rest fails and you have zero capability to resolve it. Zero. You are at the mercy of whatever Cloud provider, Host facility, kid with an iPhone controlling your VMs and whenever they get around to fixing your problem they will.
Utility? Commodity? Sure, but so are cars, yet many people will not drive a (fill in the blank for your country) because of the lousy service record or safety. Why is your Cloud provider any different.
You may ask about clustering, fail over, etc.. but that does mean you will get an answer that makes sense to you or to them sometimes.
Email is still the #1 business tool because so many rely on it. Do they have to rely on it? Not at all, but they have not made the leap yet to extended applications that notify via other methods. Maybe they did take the leap, but our customers have not yet. The customers expect to be able to interact with us through an old medium which is so easy even the term used, SMTP stands for Simple Mail Transfer Protocol, makes it sound easy. Can you plan for every contingency? No, sometimes stuff really happens you can not work around easily. But if you believe all your IT services are just commodities, then you will get what you pay for and should not expect better.
Running a mail server, and related services is not so simple and takes people that truly understand what they are looking at when they get RFC codes in reply and other "errors" as users report them.
I know, I have been doing it for 20 years, IBM, Microsoft, Google, Novell and so many long gone that it is hard to really believe anyone when they say they have a new email app. Email is an app, a huge one, and though you may argue it should just do email, we both know it does so much more and can do so much more. The problem is when the other services, which most people take for granted, stop working and your commodity or utility is unable to do anything.
Makes for a really different work day. or maybe you should spend the time thinking about how to get off the email drug and move to a better way to work.