Free ESPs (Email Service Providers) for Tax Exempt Non-Profit organizations?

My Tax Exempt 501(c)(3)non-profit organization is launching a new web application. We will be generating large amounts of emails between our users. We estimate that we will be sending and receiving approximately 50,000 emails per day. Each email will be a unique message to a specific user, e.i. not an email newsletter.

We are looking for a Email Service Provider, similar to SendGrid.com, that offers free service to tax exempt organizations, via an API or simple SMTP server. Our budget for the time being is essentially zero.

Ideally, similar to SendGrid, whatever solution we use would have the ability to receive emails on our behalf and POST them to a URL on our website as mentioned here:

http://wiki.sendgrid.com/doku.php?id=parse_api

We are looking for a Email Service
Provider, similar to SendGrid.com,
that offers free service to tax exempt
organizations, via an API or simple
SMTP server. Our budget for the time
being is essentially zero.

Reality check. I know it really sucks if reality hits you, but here we go.

How you expect the provider to pay his invoices? Like for servers, staff, electricity?

If you find a decent answer - I have a project here buying feraris and need funding for that. The idea is that people like you pay in some money so I can buy a fleet of ferraris for my use. I gladly sign you up for like 100 usd am month.

Seriously.

Running a mass mail business takes work. Takes money. Needs to be paid.

I found a comparison of e-mail service providers that might help you find what you are looking for - it has a neat guide that can give you an idea of what's available. Since cost is an issue, I would look for services that charge based on your subscriber count, as opposed to the number of e-mails you send.

I can't say, one way or the other, that any of these companies would be willing to offer their services to you for free - but it couldn't hurt to contact them and ask if they have special programs for non-profits. If the mission of your non-profit resonates with someone in one of these companies, you may find yourself with a sponsor.

You may also want to look for technical consultants/contractors that might be willing to offer their services for barter with your organization to help you build your own crm/mailing system - along with all the technicalities and training so you don't end up getting your mail server blacklisted left and right. It really doesn't take much to do this yourself, provided you do have some technology resources and something to barter with that you can leverage.

Along the same line, if you do need computers and technology, take a look at various recycling centers. They often donate computers that were discarded by other companies to non-profits. With a little poking around, it isn't very difficult at all for you to find enough hardware to run a half-decent mail server that can run some open-source software.

The key here is communication. Call around and talk to people. You won't find much of anything being advertised on the internet, nor will you get much from a group of folks trying to build a profitable startup. ;-)

Good luck!