tag:support.appharbor.com,2010-11-23:/discussions/problems/181-unable-to-read-data-from-the-transport-connection-net_io_connectionclosedAppHarbor: Discussion 2011-08-21T16:15:56Ztag:support.appharbor.com,2010-11-23:Comment/53736592011-02-16T06:55:56Z2011-02-16T06:55:56ZUnable to read data from the transport connection: net_io_connectionclosed.<div><p>AppHarbor runs on top of EC2 and it's generally very difficult
to send emails with good deliverability from EC2. Regarding the
particular error you are seeing, you may have hit the <a href=
"http://aws.amazon.com/ec2/faqs/#Are_there_any_limitations_in_sending_email_from_EC2_instances">
EC2 sending email limit</a> for the instance your app runs on.</p>
<p>There are a bunch of excelent alternatives that ensure good
email deliverability:</p>
<ul>
<li><a href="http://mailgun.net/">Mailgun</a></li>
<li><a href="http://sendgrid.com/">SendGrid</a></li>
<li><a href="http://postmarkapp.com/">Postmark</a> (used by
AppHarbor)</li>
<li><a href="http://aws.amazon.com/ses/">Amazon SES</a></li>
</ul></div>friism