“Williams acknowledges that some users may prefer or even require that their email be hosted locally rather than in the cloud for legal or privacy issues. But many enterprises that rely on the security of controlling the Exchange server themselves need to reckon with the fact they’re likely introducing more risks than they’re avoiding. “I tell customers, ‘I get it, you want to run on-prem for control reasons,’” says Williams. “But you have to start evaluating this as a liability. And that’s because Microsoft is not putting effort and resources into patching.”“The proof is in the pudding,” Williams adds. “This code base is not getting the love that it clearly and desperately needs.” And if Microsoft isn’t giving that love to your Exchange server, perhaps Exchange no longer deserves your love, either.”
Source : Your Microsoft Exchange Server Is a Security Liability | WIRED