Hi Ron,
Depending on the pod (server) of your company's instance, you will need to whitelist the following shared IP ranges respectively so that you will be able to talk to our production servers and receive test emails to your corporate inbox. Please whitelist the following:
POD1 - 209.167.231.208 - 209.167.231.223
POD2 - 209.167.231.208 - 209.167.231.223
POD3 - 142.0.162.16 - 142.0.162.31
To determine your pod, simply login to Eloqua and check the URL. For example, https://secure.p03.eloqua.com/Main.aspx#my_eloqua refers to POD3, while https://secure.p02.eloqua.com/Main.aspx#my_eloqua refers to POD2. If you do not see either p02 or p03 in the subdomain, then you are in POD1.
Hope this helps