GlobalSCAPE Knowledge Base

Optimizing Installations of Mail Express Outlook Add-In for Virtual Desktops

Karla Marsh
Mail Express - DEPRECATED


  • Mail Express version 4.x


Deploying the Outlook Add-In for Mail Express is generally straightforward in typical workstation deployments. Installation size is minimal and has no significant effect on the desktop or laptop of a given employee. However, when the workstations are virtual desktops centrally hosted, such as on a Citrix or Terminal Server implementation, all of the installations are being done against a single storage source under which all the desktops are supported, and the total storage can add up. The effect varies based on the number of installations across the number of Terminal Servers in the farm and how constrained storage resources might be. 250 installations might not be significant, but venturing into the thousands probably would.

General information on installation in such an environment is already covered in the Mail Express documentation, including any special steps that might be necessary for such multiuser environments, as well as considerations such as establishing maintenance windows in which running Outlook instances are terminated while the add-ins are installed.

Installing to mapped drives is unreliable and not recommended. Instead, you can allow the operating system to establish what appears to be a local folder that still addresses the actual remote UNC path to which a mapped drive would have been established. Below we will discuss how to leverage symbolic links (symlinks) to direct all installations across all Terminal Servers in the farm to a specific centralized network storage source.


  1. Ensure the user account has appropriate full access to the target UNC path, both through the share itself as well as the local file and folder permissions within the share, either individually or via group membership.
  2. These steps may be automated for deployment in whatever manner your organization prefers, as there are many solutions for rolling out software and other configuration in an automated fashion. Mail Express does not explicitly exclude any of the many options nor makes special provisions for any vender-specific proprietary technologies.
  3. Globalscape does not generally maintain in-depth documentation for exclusively third-party functions such as features across the many versions of Microsoft Windows. Please refer to the third party’s documentation, or search the web for applicable solutions as desired. See for example, which may be more helpful to some customers than to others.


  1. Create a symlink within the user’s environment that targets the desired UNC path. For example, for a user with the username of Eric, and a file server with the host name of, within that user’s logged-in session you could run a Command Prompt (as an Administrator, if required by UAC configuration) and input a command line like the following, with no line breaks: mklink /d "C:\Users\Eric\AppData\Roaming\GlobalSCAPE\test" \\\Share\Example
  2. In that user’s interactive session, run the installer. See product documentation for information on leveraging a parameterized silent installer if desired.
  3. When prompted to provide the install location, base it in the local path of the symlink created in the first step. For example:
  4. When prompted to provide the file store location, again base it in the local path of the symlink created in the first step. For example:

When the installation is completed, and upon launching Outlook, the Mail Express Outlook Add-In will reference and leverage that local path, which is targeting the desired UNC path behind the scenes of the operating system.

With this setup, Mail Express customers have been successful in minimizing the effects on storage utilization of large numbers of users on virtual desktops across multiple Terminal Servers.

Last Modified: Last Month
Last Modified By: kmarsh
Article not rated yet.
Article has been viewed 30K times.
Also In This Category