Four Email Delivery Services Breached in a Month: Why Japan's Bulk Mail Vendors Became a Target
Arcadia, Yumil Link, Blastmail and Y-mail, four Japanese services that send email for other organizations, were breached in October 2026, after IDCF Cloud's outage stopped others. In each case attackers reached the access the vendor uses to run its customers' environments on its own servers, and phishing went out under real senders' names, where email authentication cannot help.