SendSafely for Outlook - Legacy Plug-in vs. New Outlook for Web add-in

The Legacy SendSafely for Outlook plug-in is a VSTO app, which is an older method of integrating with Microsoft Outlook and requires users to install the plug-in locally on their desktop. This legacy plug-in is not compatible with Outlook on the Web and can only be installed on Windows desktops.

In contrast, the new SendSafely for Outlook add-in is built using a newer add-in framework for Outlook that works across all newer versions of Outlook on Windows and Mac as well as with the Outlook Web App (Microsoft 365 and Outlook.com). The SendSafely Outlook add-in can be installed by a Microsoft Administrator from the Microsoft 365 admin center. Please contact [e-mail] for the installation link. Installation instructions are available here. 

We will continue to support the legacy plug-in for the near future, but recommend that users begin to transition to the new add-in when possible. We will eventually be ending support for the legacy plug-in once the majority of our users transition to the newer add-in.