Sending Encrypted Messages

There are many ways to send email from your application. Only a few of them are worth trusting your company’s messaging to, and even fewer are able to send a high volume encrypted messages to your end users. This is the story of how SparkPost makes sending encrypted messages possible for anyone to achieve.

First, it is important to point out that we normally recommend not sending anything that needs to be encrypted over email. Personal, secure information is better handled through a direct web portal with an SSL connection if at all possible, but the reality is that stuff happens and at some point, you may find yourself writing a function to send customer financial statements as an attachment over email by the thousands.

On the surface, this does not sound that hard. Surely there must be an easy way to encrypt messages and send them to people. You could simply “pdf” or “zip” an attachment with a password, or use PGP to encrypt the whole payload, but then how do you get the cypher key to the end user or decryption? Before you know it, the project to manage encryption keys has dwarfed the original work needed to just send the message.

SparkPost users can leverage our partner integration with Echoworx to encrypt the entire email, including any attachments, and send at high volume as needed. The key management is all handled by the Echoworx application which notifies recipients, provides a secure dashboard and sends notification in multiple languages.

Using Echoworx

Echoworx can work as a plug-in or as a separate cloud service. SparkPost’s integration leverages the Echoworx cloud service which directly feeds your own SparkPost cloud account. The general topology is drawn below and shows how you can generate messages from your own creation system and choose to direct traffic to the Echoworx encryption engine or through SparkPost directly. This way you can selectively encrypt the messages that require it and send your other messages unencrypted but see all the delivery results inside SparkPost.

When Echoworx encrypts the message, it then sends a notification to the end user that there is an encrypted message available as shown in the sample below. This is sent in multiple languages and redirects the recipient to the Echoworx portal for decryption of the message.


Echoworx represents a separate partner agreement to SparkPost, so you can choose to use it or not, and it does not affect your SparkPost account. You can find more information about Echoworx on our Partner Page or at the Echoworx site directly.

Want to join our partner program? Find out more here. If you have any questions or comments about encrypted messages feel free to tweet us or drop us a note in our community slack.