I am sending email from my asp.net application, and I wanted to see if anybody could recommend a third party that will actually send the emails. Ideally they should have some sort of web service available that I can send a request to.
Mike,
Check out some of the following. They have API's that may or may not be of use/interest to you that your application could interface with. I am sure there are others, a few months ago I went through about 5-10 providers and these are the three that stuck for me.
They send out emails to your list for you and provide you with a list of what got through, viewed, subscribed, unsubscribed, etc. The best part of their services is that they have whitelist agreements with the major email providers (hotmail, yahoo, gmail, etc) so your emails don't end up in the Junkmail box.
If you wanted to automate the sending of an email through these I am pretty sure you could write an http agent to do the interaction with the website if it isn't quite there in the API how you would like.
www.constantcontact.com www.icontact.com www.mailchimp.com
Each have their subtle differences that should give you a starting point for what you're looking for. Good luck!