Assume that you use Microsoft Outlook 2016 for Mac or Outlook for Mac 2011 to connect to a mailbox on a Microsoft Exchange server. When you send an email message that contains a large attachment, you receive the following error messages in Outlook for Mac.
Error: Outlook cannot send the message <subject> because the message size exceeds the maximum limit set on the server.
Details: The message has been moved to the Drafts folder under On My Computer. Try reducing the message size by removing or resizing any large attachments, and then resend. If the problem persists, contact your administrator.
Error Code: -19738
Or, you receive a non-delivery report (NDR) in your Inbox that resembles the following:
Your message couldn't be sent because it's too large.
The message contains diagnostic information for administrators, such as the following: