I have a Windows Service that I need to access emails, I don't think I can use the Logon method as profiles are not accessible from a Windows Service so I have been using LogonHostedExchangeMailbox with the Username in the Domain\User format, this appears to logon but when I start trying to access methods or properties e.g. mRDOSession.GetDefaultFolder(rdoDefaultFolders.olFolderInbox)
I receive the following error Error in IMAPISession::OpenMsgStore: MAPI_E_LOGON_FAILED ulVersion: 0 Error: The information store could not be opened. Component: MAPI 1.0 ulLowLevelError: 0 ulContext: 646
I have outlook 2016 installed and Exchange 2019