Both DRM and Auditor allow you to send emails or email notifications. Any emails that are sent, in this case, will be done so where Dynamics GP is being launched.
Note: MAPI is used for sending emails.
If Dynamics GP is installed on your local workstation, then the MAPI Client needs to also be installed on your local computer.
If Dynamics GP is launched via a Terminal Server, then you need MAPI installed on the Terminal server.
The same holds true if you install Dynamics GP on the database server and launch it from the database server. In that case, you would need to install MAPI on the database server.
Outlook, for example, needs to be able to launch from the local workstation, Terminal Server, or database server.