In order to control WHEN the email is sent, you might have to investigate using the SAS Macro facility to conditionally send the email when a program is complete. (If you don't want to send it automatically.)
I don't really know how SAS communicates with Outlook. I suspect that you do NOT have control over "outlook-y" things like signature, fonts, etc, etc. When I send a mail using the "simple" method, it gets sent from my computer as "plain text" -- which means no fonts, etc. This happens, even though I have my Outlook default set to HTML.
If I create the email -inside- Outlook, I get my signature when I start a new mail (if I have the Tools--> Options set to insert my signature.) But, if I create the mail with SAS, then my signature is not used.
The SAS Companion for your operating system may have more information. Otherwise, you may want to work with Tech Support. (And, keep in mind that it's possible that you can ONLY send the body of the email as plain text by default because of some configuration on your system. Your mail administrator may have done something to the mail server to prevent programs from sending HTML or XML messages.)
I suspect that the SAS email is completely independent of Outlook (or any other email system). I generate emails on the mainframe and recently decided to code content_type=text/html, only to find that I had to use HTML code behind the scenes to create line breaks and whatever else I wanted.
For example, because I wanted to create a signature for my own emails, I had to code <span style=fontsize: 8pt > for the smaller size fonts.