Look at the top in the black bar on the right. Look for the icon that looks like a gear or sprocket. Click on it, and select options.
In the left hand colum look for:
Mail > Junk Mail > Safe Mailing Lists
and
Mail > Junk Mail > Safe Senders
Click on each in turn. You will see a box that says "enter an address here". Put the MSC's e-mail address (they should be able to tell you what you need to add to your safe senders list )and click the + sign.
I'm not sure you need to do it in both places but I don't think it can hurt.