* https://www.msoutlook.info/question/523 * https://docs.microsoft.com/en-us/exchange/policy-and-compliance/in-place-archiving/in-place-archiving?view=exchserver-2019 The info at the links above states you would need a specific license to see that 'In-place' archive and it does not sounds like it is made available via imap. So, either way, you would need the appropraite license that Outlook accepts and then use a different method to connect to server. The addons listed below may provide that type of link. At the links below you will find a contact email address which I suggest you use to ask the author whether their addon will allow access to be available to that particular 'In-Place' folder. * https://addons.thunderbird.net/en-us/thunderbird/addon/exquilla-exchange-web-services/ * https://addons.thunderbird.net/en-us/thunderbird/addon/owl-for-exchange/