I am developing a website - at the prototype stage, which will soon become alpha. I will give an email address for each account that allows the user to invest things - not a real email account, but only the endpoint for sending things to the site. Today, many sites provide such a service. I think the first person I saw was Photobucket, which allows you to send photos as email attachments.
My question is: what is the best way to implement such a service?
In my prototype, I wrote a POP3 client that retrieves all received mail (currently from a test Gmail account). My service processes every new mail and attachments and immediately deletes it from the email server.
Of course, I could send the email service to POP3 by email and end it. The problem is the cost. Most of the services that I have seen provide much more than I need, and they charge a fee for each account. I expect that I will have many accounts and a small amount of traffic.
Thus, I tend to send emails. I am open for Windows or Linux. The code that processes incoming emails works on Windows, but I have other services running on Linux. I have seen many open and free mail servers such as hMailServer and MailEnable (Windows) and qmail, Postfix and Exim (Linux).
I suppose I have a slight preference for Linux due to lower hosting costs, but if the Windows service can provide cleaner integration, it might be worth it. As for the features, I would like to have spam filtering, but this is not a huge priority. POP3 is suitable for searching, but a more direct API would be nice. I will need some kind of API to programmatically prepare new accounts.
All suggestions are welcome. Do you know how others implement this type of service?
UPDATE. hMailServer, , Windows. , . COM-, , .. .NET- .