When you compose a new message, click on the drop-down menu at the bottom of the pop-up window. All your posts, personal profile, and company profiles will be listed there. You can select the one you want your contacts to receive.
Your contacts will get a link to see that profile or post. Even if they are not members of RealConnex, they will be able to see them. However, this will be related to your privacy settings and locks. (If your profile is private, of course, we keep your data private and users will need to log-in and request access to view; if your settings are public, they will only need a link to view it).