Back in 2019, Microsoft announced a big change to its list of blocked file types for attachments. At the time, Microsoft stated that it was doing so to improve security by adding file extensions to the BlockedFileTypes property of existing OwaMailboxPolicy objects. The tech giant deems such file types as no longer secure for attachments and is a good way to protect customers from potentially malicious attacks from threat actors. Over time the company has expanded the block list for Outlook for...
