Hi
We don't have a customer specific spam submission in .cloud but there are a couple of ways you can submit spam samples.
Either you can log into the online portal and use the Spam Analysis Tool or you can submit samples via email to spamsample@messagelabs.com.
You mention you want to filter specific emails. Are you meaning from a specific sender? If so you can use the approved and blocked senders list.
Hope that helps
Ian Tiller
Tier 2 Senior Technical Supprt Engineer