Error Data Size Limit Exceeded during email submission
search cancel

Error Data Size Limit Exceeded during email submission


Article ID: 170190


Updated On:


Email Email Threat Detection and Response


One or more users are unable to submit false negative emails using the Outlook email submission add-in.



  • Email
  • Outlook Email Submission add-in
  • Exchange 2013
  • Exchange 2016


The Outlook submission add-in sends a request to Exchange Web Services (EWS) to get the base64 encoded email content. However, if the EWS response is greater than 1 Megabyte, the email content would not be retrieved due to the size limitation.

The size limit applies to Exchange 2013, 2016 on-prem solutions. There is no limit when submitting on a hybrid environment with Office 365, standalone Office 365 or Exchange Online.

For more information about these type of EWS errors, see EWS Response Codes.


If the false negative emails cannot be submitted using the Outlook email submission add-in, these emails would need to be reported manually.

Submit false positives for legitimate email flagged as spam

Submit false negatives for email not flagged as a threat