Looking for some recommendations on Email Gateways. Hoping to catch the attention and get ideas from Exchange Admins, Cyber Security Professionals, folks who work the security field, email is a big open doorway for attacks that I want to shut.
It must be able to do the following:
Spool email (save emails in a cache state while servers are down unexpectedly),
Email Continuity (allow users to view email during extended mail server downtime)
Incredible spam, virus, etc. filtering.
Users - 300 - 500
Exchange 2013 environment , on-site premise
The following gateways have been considered already, looking for additional choices.
Edgewave and Proofpoint
It has virus, spam filtering. You can setup enforced encryption on emails for certain domains. If you need, you can configure DLP.