Renaming Outlook files not working

Dear Debbie,

I tried to replicate your issue but renaming worked normally on my side, so it may come down to something specific to the item type or account involved. Since you are changing case only rather than the name itself, try renaming the item to something completely different, for example adding a character or a different word. Case only changes are sometimes treated as no change at all and reverted, whereas a genuinely different name will stick. If the different name holds but the all caps version does not, that tells us a lot. Additionally, could you provide a few more details:

• Are these email folders, attached files, or Outlook data files?
• Is the account Microsoft 365/Exchange, Gmail, or another IMAP account?
• Are these folders you created, or default folders such as Inbox and Sent Items?
• Does the name revert immediately or after Outlook synchronizes?
• Can you rename the folder successfully in Outlook on the web?
• Is anyone else in your organization seeing the same thing, or is it just your mailbox?

If these are custom email folders, try renaming one through your email provider’s web interface. If the web rename remains but classic Outlook reverts it, the issue is likely local to Outlook. If it also reverts online, the mail server is restoring the original name. This can occur with IMAP synchronization.

Let me know how the different name test goes and we can take it from there.