Using classic Outlook for Windows in business environments
Could you please go to File > Account Settings > Account Settings, check the Type column, and confirm whether the account is listed as Microsoft Exchange, IMAP, or POP?
If it is an IMAP account, Outlook obtains the folder list from the mail server. In some IMAP configurations, a manually arranged folder order may not persist after Outlook refreshes the folder list or restarts.
In that case, the practical workarounds are to:
- add numbers to the beginning of the folder names, for example, 01 DOCTORS & HOSPITALS and 02 SAFFRON WALDEN; or
- add the frequently used folders to Favorites and arrange them there.
If the account is Microsoft Exchange or POP, please try the following:
- On the Folder tab, make sure Show All Folders A to Z is not selected.
- If the order is still reset, repair Office Professional Plus 2021 through Settings > Apps > Installed apps > Office > Modify. Start with Quick Repair, followed by Online Repair if necessary. You may also refer this article: Repair an Office application
- If the issue remains, create a new Outlook profile for testing, as the current profile may not be saving the folder-pane configuration correctly.
Please give it a try, and if there are any updates, just leave a comment under this post. I'll get a notification and will reply when I can.
Thank you so much for taking the time!