error "554 5.2.0" STOREDRV.Deliver.Exception"

Hello Prachitosh Sahu,

The error"554 5.2.0 STOREDRV.Deliver.Exception" is usually related to the recipient's Exchange mailbox rather than the Outlook client. It can be caused by mailbox quota issues, mailbox folder corruption, or other mailbox configuration problems.

Please try the following and let me know the information:

1. Confirm whether the issue occurs when sending to all recipients or only a specific recipient.
2. Send a test email using Outlook on the web (OWA) to rule out an Outlook client issue.
3. Check whether the email can be sent without attachments or with a smaller attachment.
4. If only one recipient is affected, you should check:
   • Mailbox quota and recoverable items quota
   • Mailbox health/corruption issues
   • Missing mailbox folders such as the Clutter folder, which is a known cause of this error.

As a possible resolution, please review NDR errror 554 5.2.0 STOREDRV.Deliver.Exception - Exchange | Microsoft Learn.
Microsoft documents a known Exchange Online issue where this error can occur if the Clutter feature is enabled but the Clutter folder is missing from the recipient mailbox. Disabling Clutter or correcting the mailbox configuration may resolve the issue.

If the issue persists, please provide the full NDR (with personal information removed) for further investigation.