Review my Idea: Email-based database service

I've been thinking about this idea over the past few days. I've even already written code for it and have a functional prototype. But, everyone I tell the idea to doesn't seem to grasp the concept or just can't see why it would be useful.

My idea is simple. The idea: a hosted database service (a la MongoHQ) with an easy and highly accessible CRUD interface via SMTP (a la Posterous). It would be accompanied by an API for CRUD, also - perhaps REST.

The idea came to me while thinking about writing my own SMTP-based blog, like Posterous. I wanted to write my own blog that I was able to write to using any email client I had, instead of using some annoying WYSIWYG editor. But then a friend suggested, "why not generalize it for more than just blogs"? I'm not sure to what extent he meant, but I immediately envisioned something similar to Posterous but more generalized. Basically, a database that anyone could perform CRUD on using their email client.

Why email? Everyone has it. It's easily accessible. There are email client implementations in pretty much every environment you can think of.

It obviously wouldn't be for heavy read/write traffic database applications, but more for casual users that don't fully understand the internal workings of how to use their own database. It could perhaps be used by myself to write my own Posterous-esque blogging platform. It could be used for email storage and backup. It could be use for file sharing, backing up files with associated meta data. A simple API could provide non-SMTP read access to your data - perhaps REST.

I feel like this idea excites me because of two reasons, A) it has a clear cut hosting-based business plan, which none of my ideas ever do, and B) I don't even know if I fully know how this is entirely useful or what the applications of it could be. I haven't gotten very good feedback on it, though. So, what you think about this?

Here is what I have running for it so far. It's just something I wrote in a single afternoon as kind of a proof of concept for myself. I wrote a simple SMTP server that does nothing but handling incoming emails and performs some simple, crude authentication on them. Authentication is done by signing up on the site, downloading the provided "db.auth" file. To submit data to the database, address an email to "db@collabreate.co" and attach the "db.auth" file. The records will appear on the website. There is no other functionality in this demo.

http://collabreate.co:8080/records/

The domain is just something I use to play with - it's not related to this particular idea.

So, what do you all think? :P