https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=38338 --- Comment #79 from David Cook <dcook@prosentient.com.au> --- Turns out it pays to read the instructions... https://learn.microsoft.com/en-us/exchange/client-developer/legacy-protocols... The final step was to create a service principal and give it mailbox permissions for the particular account in question. I'd hunted and hunted for the UI to do this, but couldn't find it. The only way I could get it done was using "Exchange Online PowerShell" which is an extension module for regular Powershell that sits on your desktop. It's not great, especially if you work with multiple different systems I think. But... it worked. Just took a lot of effort. I am starting to come around to the idea of using the Microsoft Graph API (as Brian does on bug 42179) to be a much more user-friendly of setting up email integration with Microsoft. -- You are receiving this mail because: You are watching all bug changes. You are the assignee for the bug.