The issue with the "From" field in sent folders displaying as /o=First Organization may be related to how Outlook handles account configurations and the display of account names. If you are experiencing this, it could be beneficial to check your account settings and ensure that they are configured correctly. Additionally, if you are using multiple accounts, make sure that the correct account is selected when sending emails.
For more specific troubleshooting steps or if the problem persists, consider consulting the Outlook support documentation or community forums for additional guidance on resolving display issues in the "From" field.
References:
- The From field in a meeting request does not list all accounts in Microsoft Outlook
- Emails that you forward are not saved in the Sent Items folder in Outlook
- Performance and synchronization problems when you work with folders in a secondary mailbox in Outlook
- Email messages are stuck in Outbox in Outlook 2016 for Mac