You can setup your DNS to include our servers in your SPF record (so that your campaigns will be SenderID authenticated).
If you have access to and can modify your DNS, add this bit of code to your SPF text record to enable SenderID Authentication for all your campaigns:
include:cemsc.net
For example, your SPF record might look something like this:
v=spf1 mx include:cemsc.net ~all
If you have absolutely no idea what any of this means, print this out and give it to your IT group