I hate starting out on a new forum with an issue but here we go After the update all my flags in Outlook are gone! Weirdly even after adding new ones straight after syncing with IMAP these are gone as well. Interestingly they appear fine on my iPhone and on one of the PC's in our office. It's not a server issue as I've tested this with our business one, GMail and Yahoo. Has anyone came across it yet? The mess-up process is simple: Add Follow Up Flag to an e-mail -> Sync with server fetching mail -> Flag's gone from Outlook (and syncs on all other machines connected to this account). Go Microsoft.