EWS shared mailboxes I have full delegate access to used to work fine but now are returning an error message:
11:09:47 [delegated account name] [Exchange Web Services] MailClient.Storage.Application.OperationException
—> Microsoft.Exchange.WebServices.Data.ServiceResponseException: The specified object was not found in the store., Can’t connect to the mailbox of user Mailbox database guid: 3ab74262-9a11-4646-a4ff-68bae7c20ab1 because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently.
The shared mailbox is setup as an additional account (not an auto-mapped mailbox and not an additional mailbox) and the principal account has full access rights to it on M365 tenant where I’m the admin.
I can receive emails in, but cannot send from, the shared mailboxes in eMclient.
The shared mailboxes work fine in outlook desktop classic/OWA and eMclient android.
I have raised a support ticket with MS and with eMclient. eMc says it’s a MS issue and MS says it’s an eMc issue.
eMc support has been keener to wash their hands off on this than to resolve: first claimed I don’t have access to the mailbox (!), then confirmed my mailbox access rights on a Teamviewer session, then offered a refund (!), then proposed that I start with a clean sheet from anew and create a new database, which I did with the same results. eMc support claims that they cannot replicate the issue from their end - but how could they, it’s an issue on my installation (cache?)! What eMc hasn’t done is to look into the GUIDs, what’s keeping my machine’s cache stale, why the installation on my machine doesn’t speak to the EWS server correctly, while the android installation and the outlook installation work fine.
MS is still at pre-escalation support level.
Please help.