Any web services with APIs for outsourcing webapp email?

Question

My webapp needs to send customized messages to members and I'm wondering if there is an inexpensive and easy to use web service that would meet my needs. The types of mail I will be sending include:

• New account activation email (sent ASAP)
• Daily status report of user's account (sent anytime)
• Event reminders (sent at specific time)

Specifically, I would like the following features:

• RESTful API to add an email message into the send queue
• A way to add a priority to each message (account signup activations should be sent immediately, while a daily status report could be sent anytime each day)
• They manage the sending of mail and the processing of bounces
• Possibly, they manage opt-out/opt-in features
• They offer features such as DKIM, VERP, etc.
• If their service determines an address is undeliverable (via VERP or other means, a user unsubscribes, etc), they make a RESTful call to my web service to notify me
• Nice if they had some reporting features, WebBugs, link tracking, etc.

What I am NOT looking for is an email marketing service that caters only to sending out copies of the same mail to masses of recipients. I need to send out unique and custom messages to individuals. I had a chat with MailChimp about using their services for sending these types of messages and they said their service does not support customized emails per recipient.

Edit: I just discovered a service called JangoSMTP that appears to meet many of my requirements. It provides an API for sending mail, supports DKIM, bounce management, and even feedback loops. Unfortunately, their idea of inexpensive doesn't mesh with mine, as it would cost $180/mo to send a single daily message to my 1000 users.

Answer 1

Well, nobody seems to have an answer for this question. Since posting the question, I've found several solutions.

SendGrid

This seems to be the service of choice by the current collection of hot startups. For instance, it's used by GetSatisfaction, HootSuite, and Foursquare. I just started looking into it, but am liking what I see so far. With their $80/mo plan, I could send up to 50,000 messages. This would easily cover a daily message to my 1000 users, and leave room to grow.

JangoSMTP

This service appears to meet many of my requirements. It provides an API for sending mail, supports DKIM, bounce management, and even feedback loops. Unfortunately, their idea of inexpensive doesn't mesh with mine, as it would cost $180/mo to send a single daily message to my 1000 users.

StrongMail

I'm not sure if this really supports what I'm looking for, but it sounds like it possibly does. However, I don't like that there is very little information on their site, no pricing details, or anything. I get the sense they are for companies with big budgets. Probably won't even look into them any further because of this.

SubEthaSMTP

This isn't a web service with an API, but if I decide to implement my own custom solution, SubEthaSMTP is probably the tool I would use. Getting it to handle VERP bounces is quite easy:

class BounceListener implements SimpleMessageListener { 
        public boolean accept(String from, String recipient) { 
                return recipient.startsWith("deals-"); 
        } 
         public void deliver(String from, String recipient, InputStream data) throws TooMuchDataException, IOException { 
                int atIndex = recipient.indexOf("@"); 
                String rec = recipient.substring(0, atIndex).replaceAll("=", "@").replaceAll("deals-", ""); 
                YourCode.markAsBad(rec); 
        } 
        public void main(String[] args) { 
                SMTPServer smtpServer = new SMTPServer(new SimpleMessageListenerAdapter(new BounceListener())); 
                smtpServer.start(); 
        } 
} 

Conclusion

At the moment, I'm planning to try out the free version of SendGrid and see what I think. If it works well, I may upgrade to the Silver plan for $80/mo. However, after seeing how simple SubEthaSMTP makes VERP bounce handling, I may opt for running our own mail server. We'll eventually need to do this anyway as we grow.

Answer 2

There is also Postmark, a service we just recently launched. If you are interested let me know and I can offer some extra credits to try it out.

Thanks, Chris