Ask HN: Email Software for the Enterprise

Email overload is a nightmare. Corporate email software (e.g. MS Exchange-Outlook) does a mediocre job of organizing large volumes of email. I have an idea for creating an email server-client suite that would automatically organize your email. But even if I create something that beats Exchange-Outlook hands down, most large companies probably won't buy their email software from a young startup. And a small company won't have much of an email overload problem.

My current plan is to sell to startups, and hope that some of these will grow to be large companies, and thus large customers. Once I have a few major customers, my startup will have the legitimacy to be able to sell software to the likes of GE. Any thoughts on this plan?

Has anyone here been successful in selling software to enterprise customers? If yes, how did you overcome the 'startup legitimacy' issue?

Is there anyone here who works in the IT department for a medium or large sized company, and has bought software from a startup? What would be your major concerns about buying software from a startup?

Thanks in advance for any feedback.

PS: I have already thought about creating email software for the consumer market, but my ideas about self-organizing email would work much better in the context of corporate email.