How SafeSend Works

When installed, SafeSend requires validation each time you send an email to an external recipient. You will need to confirm all external recipients of an email before it leaves the network. Upon hitting “Send” or “Send Secure,” the SafeSend pop-up window will appear. To confirm the recipients or any attached file, click on the checkbox beside each of the external recipients (and file if applicable) and hit the Send button.

What's Included

When you receive your file, it will include the following files:

  • Get_Started_With_SafeSend
    • Helpful information and links to help you get started
  • (SafeSend PC add-in)
    • Administrative Templates 
      • For use with Group Policy to manage settings when the SafeSend PC add-in has already been deployed
    • Admin Password 
      • Administrative credentials for local access to SafeSend settings
      • Not applicable for Trial licenses
    • SafeSendSetup
      • Installer package (.MSI) for the SafeSend PC/COM add-in
  • SafeSendWebAddinWeb_v.r.m.b (SafeSend Web add-in)
    • SafeSendWebAddinWeb
      • Web server folder
    • End-user License Agreement (EULA)
    • safesend-manifest.XML
      • Editable file where you add your web server domain

For these instructions, you will need everything within the SafeSendWebAddinWeb_v.r.m.b folder mentioned above.

Install and Configure SafeSend Web Add-in

While SafeSend v4.6 will work with any .NET CORE 3.1 capable web server, we recommend using IIS (Internet Information Services). If using IIS, you'll need to download and install the .NET Core Hosting Bundle found here.

Important Notes

Microsoft requires the site in which the add-in is hosted to be SSL secured.

Deployment of the SafeSend web add-in can take up to 12 hours to propagate the network.

Any changes made to Settings.json require the website to be restarted to take effect. This should be done outside of normal operating hours to avoid potential service interruptions.

- Download and extract

- Create folder c:\SafeSend on the machine hosting IIS

- Copy the contents of the extracted folder SafeSendWebAddInWeb_4.6.1.55 to c:\SafeSend

- Open internet Information Services Manager

-  Right-click on "Sites" -> select "Add Website"

   - Site Name = SafeSend

   - Physical Path = c:\SafeSend 

   - Click "Ok" to save changes

- Click on "Default Web Site" and then "Stop" in the righgt panel of IIS Manager

- In the left panel click on "Application Pools"

- Right click "SafeSend" and select "Basic Settings" 

   - .NET CLR version = "No managed code" - click OK

- Browse to C:\SafeSend\SafeSendWebAddInWeb

- Open file settings.json using notepad

- Adjust the following settings:◦

     - EmailProviderURL 

        - If you are using Microsoft 365, the EmailProviderURL should already be correct

        - If you are using an Exchange Server, you will need to update that setting as appropriate

     - Set LicenseKey 

     - Set SafeDomains 

     - Set EnablePlatform to True if you will be using Web, PC, or Mac and False for the platforms you will not be using

        - If you are using Microsoft 365, Web Add-in works for all 3 available platforms

        - If you are using Exchange Server, Web Add-in does not work for Outlook for Mac or OWA in Safari

- If you are using O365 you will also need to modify safesend-manifest.xml

- Open C:\SafeSend\safesend-manifest.xml with Notepad

   -  Search for all instances of the 'localhost' domain and replace this with the site where the add-in will be hosted

Deploy SafeSend Web Add-in

When using the SafeSend web add-in, there are two ways to deploy this to your organization:

  • Microsoft 365
  • Exchange 2019

Refer to the latest release notes for full system requirements.

Centralized Deployment via Microsoft 365 Admin Center

For full, up-to-date, details on deploying add-ins in Microsoft 365, visit

Deployment via Exchange 2019

For full, up-to-date, details on deploying add-ins for Outlook in Exchange, visit