WFBS 9.0 currently does not support OL2013 Click-to-run deployment due to COM interface issues.
Below are options you can implement to avoid receiving spam emails.
If you are using Exchange Server on-premise, you may upgrade your license to WFBS-Advanced version. This version has the Messaging Security component that protects the Exchange Server from receiving spam emails and emails with malicious attachments.
Use Trend Micro Hosted Email Security (HES). This is a hosted service that also protects users from receiving spam emails or emails with malicious attachments. As a hosted service, it does not require additional hardware/software. All scanning hardware and software are operated and maintained offsite at Trend Micro’s secure data centers. This allows HES to work with Exchange Server on-premise or even if your emails are hosted by third-party hosting providers.