Mail Span Filter installation

Im Looking roward for a solution in frond of my Exchange with that features :
- With Web GUI
- The option to forward emails with S/Mime Certs
- Add a Signature/Disclaimer on User Base
- Filter option Spam and Quarantiane
- The option to add a External SMTP Relay / or send out direct to the Internet
- DKIM/DMARK Management
Your job is to install and to explain to me
Thank you