Secure by Design


Authentication Security: Our service uses Office 365 OAuth to authenticate users. No password is ever collected, transmitted, or stored by us.

No Accessible Online Signature Views: Online signature views, when needed, are via encrypted URL’s, rather than via public endpoints.

No Access to Your Email: Our process does not require that your email messages be routed through our servers for the signatures to be applied or “stamped”, and therefore we have no access to your email.

Add-in Security: Outlook add-ins are different from COM or VSTO add-ins, which are older integrations specific to Outlook running on Windows. Unlike COM add-ins, Outlook add-ins don’t have any code physically installed on the user’s device or Outlook client. For an Outlook add-in, Outlook reads the manifest and hooks up the specified controls in the UI, and then loads the JavaScript and HTML. The web components all run in the context of a browser in a sandbox.

Outlook on Windows uses a JavaScript file, while Outlook on the web uses an HTML file that can reference the same JavaScript file. References to both these files are supplied in the Resources node of the manifest (XML) and the Outlook platform ultimately determines whether to use HTML or JavaScript based on the Outlook client.

Per Microsoft’s guidance, our event-based add-in is short-running, lightweight, and as non-invasive as possible. We use the “event.completed method” to signal that our add-in has completed processing the launch event. If, for any reason the add-in has remained open, Outlook automatically ends it when the user closes the compose window.

email signature add-in scan results

For additional technical information, read Microsoft’s Privacy and security for Office Add-ins article.

Server Security: Our servers are secured using industry best practices. Access is limited to only Digitech Branding employees who need access for business purposes. Our services are hosted on Heroku and AWS and are protected with Cloudflare. Encryption is via Cloudflare “Modern TLS Only” forcing all HTTPS traffic to be served over TLS 1.2. Our primary data locations are AWS US East (N. Virginia) and AWS US East (Ohio) with AWS US West (N. California) used for some data backup. Additionally, we maintain an offline backup that can be started in emergency in AWS Europe (Ireland) - this is compute only (data still resides in the primary locations).

Level 1 Data: Due to the nature of email signature data, we work exclusively with level 1 data.

Penetration Testing: We contract for annual penetration testing and promptly rectify any issues or vulnerabilities that are uncovered.

Application Vulnerability Scanning: We employ SonarCloud to scan our code (back-end and O365 add-in) for vulnerabilities.

Superior Performance

The single most important aspect in email signature performance is the accessibility and delivery speed of the images in the signature - image reliability affects both senders and recipients.

We utilize an optimized edge network with images residing at 300 centers around the world.

email signature images from the edge

Since 2017 we’ve been serving roughly 1.6 billion images per month (2 terabytes of data) without any significant outages*.

* In the last 6 years we've had approximately 50 outages of under 60 seconds and 4 outages of under 10 minutes, and zero outages in excess of 10 minutes.