SSLPost Secure and Tracked Email
Usage and Fees
Technical data

Securely Deliver Documents by Email

Conventional email is just like sending a postcard – anybody could potentially read it along its delivery path from the sender to intended recipient. FlexStream now offers a robust secure and tracked email service for sensitive business documents. FlexStream makes it easy to select the documents to be emailed, send the emails with the confidence that they will reach their intended recipients without passing into the wrong hands, and offers extensive tracking, audit, and follow-up functionality.

  • Channel Selection

    FlexStream has output management features that allow you to process documents and distribute them using multiple methods: email, secure and tracked email, output to printer or PDF-file, and archiving.

    FlexStream allows you to select which documents from a document stream you want to be emailed, based on information contained in the document or over a linked database. This allows for a transition from paper to email based on your or the recipients preferences.

  • Secure Email

    Secure and tracked email is a simple and cost effective method by which you can safely send documents, even very large files, over the Internet in a secure, managed and audited manner. All attachments are encrypted to ensure complete confidentiality using high-grade encryption algorithms.

    Recipients receive a personalized, standard email containing a link, which is used to access their encrypted file held on the secure server and download the content over a secure (HTTPS) Internet connection.

  • Tracking, Audit and Follow-up

    With full delivery and receipt audit reporting included, you are able to track and trace the document throughout the delivery process. FlexStream will show you time of sending, delivery, and the date and time the attached document was opened by the recipient.

    If you have sent the document through secure and tracked email, and the recipient does not open it within a certain time frame, which you can monitor through the built-in audit process, you can choose to reissue using the same or a different method. Audit reports can be exported.

FlexStream Document Processing with World Class Email Security

FlexStream uses the SSLPost service for its secure and tracked email. This service is a sophisticated system of processes, which deliver electronic mail in a highly secure environment ensuring end-to-end encryption and maximum security. The service is deployed as a public SaaS solution.

  • Significantly reduce costs by saving printing, material, and postage.
  • No investment in email infrastructure required, no email server needed. No special setup, the service can be used without intervention of IT specialists. No worries about becoming blacklisted when sending large amounts of emails.
  • No workflow intervention. Processes PDF-documents generated by any system. Complete flexibility in selecting documents to be emailed.
  • Securely send emails with attached documents up to 6MB. Sending large document attachments in this manner will prevent any blocking by the recipient’s email server because of file attachment size limits or other email settings.
  • Track and trace sent emails with no recipient intervention. Recording of date and time the email was sent, delivered, and when the attached document was opened and read.
  • Easy to use for the recipient. Looks like a 'normal' email and can be used without additional software installed.

All Secure and Tracked Email Features Needed

FlexStream’s powerful document output processing features that allow you to dynamically select the delivery method of each document, together with the highly secure email and tracking service give you an unsurpassed solution for emailing your documents.

Channel Selection

  • Select delivery method based on data contained in the document or based on a lookup in a linked database.
  • Manually select documents for email.


Channel selection

Secure Email


Secure email

  • Design your own email body text with variable elements to personalize the email, subject and file name of the attached document.
  • Military grade levels of encryption during transit of the document.
  • Securely transfer documents of up to 6 MB. No bouncing of emails due to user or server settings.
Tracking and Audit

  • The FlexStream datasheet shows delivery status, including date and time of sending delivery, and opening by the recipient of the attached document.
  • Select a follow-up action based on the email status of a certain document for a recipient, e.g. reissue a mail or send the document by post if the document was not opened.
  • Export an audit report of all emailed documents.


Email tracking


Packages for any need

There are no fixed costs for using the secure and tracked email service. Fees are based on pay per use pricing. Packages with emails for low to high volumes are available, making the service attractive for both smaller and larger users.

The use of the secure and tracked email service is available in FlexStream Professional and requires maintenance on the software.


Secure and Tracked Email Technical datasheet

FlexStream uses the SSLPost service for its secure and tracked email. The SSLPost Web Application is deployed as public SaaS (software as a service) solution. FlexStream provides registered users an easy-to-use interface to use the Web Application to send encrypted files and emails and manage all audit logs relating to opened or unopened communications.

The secure and tracked email service allow you to send a large electronic file (PDF-document) to a secure server where it is held and encrypted until your recipient picks it up by following the simple instructions within their notification email. With full delivery and receipt audit reporting included, you are able to track and trace the document throughout the delivery process.


SSLPost Secure File Transfer is a simple and cost-effective method by which you can safely send files up to 6Mb over the Internet in a secure, managed and audited manner. Recipients receive a standard email containing a link which is used to access their file held on the secure SSLPost servers and download the content once user authentication has been performed successfully. All access attempts, successful or not are recorded and sealed. Therefore the audit log cannot be tampered with.

In addition to ensuring the security of the electronic documents transmitted, the secure and tracked email solution also utilises a ‘web beacon’ pixel to check whether a notification email containing the link has been delivered to the client's email server and also when it has been opened in the client's email program. This web beacon solution is commonly used by email marketing companies for their standard email tracking facilities.


Every document sent via SSLPost is encrypted with a unique AES 256-bit session key, and the contents are additionally signed with an RSA signature so no one can tamper with it.

SSLPost uses a mix of block and transport encryption processes. Secure Socket Layers (SSL) are used with a 256-bit key to encrypt communication from the sender to the SSLPost servers (most credit card transactions only use 128-bit encryption). The SSLPost servers encrypt using block encryption, which uses a combination of 256-bit symmetric and 2048-bit asymmetric processes. The result is then encrypted with a 256-bit seal key which is used to track access to the data if the recipient's private key is held client- side. Finally a hash value of the message is calculated and signed with the sender's private RSA key.

The electronic file is then stored encrypted on the SSLPost servers and a standard internet email is created containing a unique hyperlink to the stored file and any unencrypted message text that has accompanied the file, from the sender. This email is sent to the recipient over normal email (i.e. SMTP) and once they have clicked the hyperlink the decrypted file is only made available over a 256-bit SSL secure link once recipient authentication is successful.

Copyright © 1993 - 2024 Flex Systems B.V. Best viewed in Chrome, IE or FF. HTML5 Powered