NOTE: You must be a premium member to create additional folders or add / save messages from your inbox to your existing storage folders using the Move button. (professionalsinglesonline.com)
You can place them in a cloud storage folder like Dropbox or back them up to a USB drive. (howtogeek.com)
A Premium member has access to all site features including but not limited to: Initiate an email to / from any members, IM other premium members, expand your Inbox / Outbox storage capacity, create new storage folders, view other members who have viewed your profile, add custom keywords, advanced search features, and new features first. (professionalsinglesonline.com)