Repeated HTTP errors on the Message Trace input are often caused by API throttling, expired OAuth tokens, or permission changes rather than the TA itself. I'd verify the app registration, confirm the account still has the required Message Trace permissions, and check whether Microsoft has started rate-limiting the requests. If the data itself is more important than troubleshooting the API, another option is to export the Microsoft 365 mailbox directly instead of relying on Message Trace. We've used the BitRecover Office 365 Backup Tool for that. It supports multiple Microsoft 365 accounts, incremental backups, and exports to PST, MBOX, EML, PDF, etc. One thing that's easy to overlook is that Microsoft may return temporary 429/5xx responses even when authentication is correct. Any workflow that supports automatic retry and resume will usually be much more reliable than restarting the entire process after every transient failure.   ... View more