Yes, you will be able to create message rules/filters to have messages moved directly in to the Junk folder. You will also be able to create a list of allowed senders or block messages by email address or domain.  Also to note, PenTeleData Webmail uses a learning system for SPAM.  If you are receiving SPAM, simply drag and drop to the folder, and the system will start to learn, based on criteria of the message contents.