Hi Mary, I moved your question to the Products & Support category for more visibility.
Mary,
There's a few ways to do this. If you already have a campaign or segmentation for classifying leads as marketing suspended, you'd add this in there. If not, you could just create a smart campaign: Smart List looks for all leads in a certain company (try different spellings) OR that have an email address that contains @domain. Then the flow would be to change Marketing Suspended to TRUE.
-Kim