I need to send a few but important email notifications to individual users. For instance, when they register their software I send them a confirmation email. Right now, I am using 'sendmail' from my Perl CGI script to do the job. Most of my automated email are lost or marked as junk. Unfortunately, I am using shared hosting services and not a very good control over the SPF and SenderID DNS records. Even more bad, some other user of that shared server has been infected with some kind of SPAM-BOT and the IP is now blacklisted until further notice! Anyway I just don't want to deal with this kind of headache. I am looking for an online service that I will be able to subscribe to and pay something like 0.10$ per email I send with no monthly fees. I just need and API to be able to send the email from PHP or Perl code I will have to write. I have been looking around at all those "Email Sending Services" and they are all wrapped around creating campains and managing lists for bulk email marketing distribution and newsletters. But remember, I want to send an email notification to a "single" recipient. So far, I have look at MailChimp, SocketLabs, iContact, ConstantContact, StreamSend and so many others to no avail. I have seen one comment at Hackers News saying that MailChimp have an API for transactional e-mails (i.e. ad-hoc ones to welcome a user for example). So you're not just restricted to using them for bulk emails But I cannot find this in the API documentation supplied, maybe this was removed. Any suggestions out there. Here is a summary of my requirements: Allows ad hoc sending of email to a single recipient. Throughput may well be throttle I don't care, i am sending like 2-5 emails a day. API available in PHP or Perl to connect to that web service. Ideally I can send HTML formatted emails, otherwise I will live with text only. Solution not too expensive, between 0.01$ and 0.25$ per email would be acceptable. No recurring monthly fees.