Cloud email: Top threats & security best practices Cisco Umbrella VIDEO 1 Today, around 27% of organizations embrace public cloud email services, a number expected to rise to 70% by the end of the year â the public cloud email market is growing, and with a 56% market share, Microsoft 365 is leading the transformation. But as cloud email use grows, so too do the threats targeting inboxes â in fact, business email compromise (BEC) accounts for more than $1B in losses per year. Download this asset to learn more about: The cloud email movement How Ciscoâs Cloud Mailbox Defense is helping to protect inboxes And more