out look draft error

Question

the operation cannot be performed because the message has been changed

Answer 1

Hi @Support, 

Good day, and I appreciate the clear description of your issue.  

I am writing to assist with the error message in Classic Outlook stating that the operation cannot be performed because the message has been changed. 

This conflict typically arises when the Outlook Autosave feature and a background process, such as a synchronization task or a security scanner, attempt to modify the draft at the same time. Because the metadata of the message is updated by a secondary source, the version currently open on your screen is viewed by the system as outdated. Consequently, Outlook prevents the action to ensure no data conflicts occur during the transmission of the message. 

To understand the scenario more clearly, could you please share the details below. 

1. Does the error occur only after the draft has been left open for a while, or can it happen immediately after you start composing? 
2. Does this error occur primarily when you have attachments included in the email draft? 
3. Are there any third-party add-ins, such as a CRM or antivirus scanner, currently active within your Outlook? 
4. Does the issue persist if you use the "Pop Out" button to compose the message in a separate window instead of the Reading Pane? 

In the meantime, I would like to provide some context and potential steps to help you move forward. 

1/ Adjusting the autosave frequency 

• Navigate to the File tab in the top left corner and select Options. 
• Click on Mail in the sidebar and scroll down until you find the Save messages section. 
• Uncheck the box labeled Automatically save items that have not been sent after x minutes to prevent the software from trying to save while you are typing. 

2/ Isolate add-in interference via safe mode 

• Close Outlook completely and press the Windows Key + R on your keyboard to open the Run dialog. 
• Type outlook.exe /safe into the box and press Enter to launch a clean version of the application. 
• If the error does not occur in this mode, go to File > Options > Add-ins, select COM Add-ins at the bottom, click Go, and uncheck active items to find the specific software causing the conflict. 

3/ Refreshing the auto-complete cache 

• Open the File menu and click on Options. 
• Select the Mail tab and locate the section titled Send messages. 
• Click the button for Empty Auto-Complete List to remove any cached recipient data that might be triggering a validation error during the draft phase. 

4/ Recreate the draft and refresh the local Outlook profile if needed 

• Open the draft, select all content, then copy it. 
• Close the draft, open a new email, paste the content, then add recipients, subject, and attachments again. 
• Send the new message, then delete the original draft that cannot be sent.  
• If the issue continues, create a new Outlook profile from Control Panel, Mail, Show Profiles, then open Outlook with the new profile and test drafts again. 

Once you share your answers to the three questions above, I will tailor the next steps to your exact account type and configuration. 

I hope this response has helped address your question and clarify the behavior you're experiencing. Please feel free to reply if you have any further questions, I would be happy to assist further.   

Thank you for your patience and your understanding. I look forward to continuing the conversation.

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Answer 2

The error "The operation cannot be performed because the message has been changed" in classic Outlook usually occurs when Outlook or the server modifies the item (via autosave or server assistants) while it is still open. Resolution and workaround depend on the scenario.

1. If this happens when creating or updating calendar meetings (especially as a delegate, or when adding Teams/Skype):
   • Avoid leaving the meeting open for a long time before sending.
   • Send the meeting within about 1.5 hours of first saving it to Drafts to avoid server-side Event Based Assistants (EBAs) changing the item before it is sent.
   • Adjust or disable Autosave so Outlook does not save too frequently while editing:
     1. Go to File > Options > Mail.
     2. In Save messages, either clear Automatically save or increase the delay before autosave to a higher value (for example, 10 minutes or more; allowed range is 1–99 minutes).
   • If acting as a delegate and the issue persists, consider using Outlook on the web (OWA) to create or edit meetings, as OWA is not affected by this specific problem.
   • Ensure the mailbox is on a service build 15.20.2730.00 or later (use the Connection Status dialog as described in the linked article) because a fix for one variant of this issue is included in that build.
2. If this happens when updating meetings in own or shared calendar more generally:
   • After sending a meeting, wait 1–2 minutes before making further changes (such as adding attendees or changing time) so the meeting can fully sync to the server.
   • If the error appears, dismiss it and then save changes again.
   • Increase the autosave interval as described above to reduce conflicts with EBAs editing the item while it is still being composed.
3. If this happens when moving emails between IMAP folders:
   • This is a known intermittent behavior when moving items between IMAP folders, especially large folders.
   • Workarounds:
     • Switch to a different folder, then back to the source folder, and try the move again.
     • Close and restart Outlook, then perform the move again.
4. If this happens when sending a message left open for a long time in an Exchange Server 2016 on-premises environment (online mode):
   • The conflict is caused by Outlook autosave and a server agent modifying the message while it is open.
   • Install Exchange Server 2016 Cumulative Update 15 or a later cumulative update on the server to apply the fix.

If the environment matches one of the scenarios above, apply the corresponding steps (autosave adjustment, timing of edits, IMAP move workarounds, or Exchange server update) to prevent or reduce the error.

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References:

• The operation cannot be performed because the message has been changed
• The operation cannot be performed because the message has been changed error when a delegate creates a Skype or Teams meeting in Outlook
• Users may experience an error when updating a meeting in their own or a shared calendar
• You receive an error when moving emails to another IMAP folder
• “The function cannot be performed…” error when you send a message that’s open for a long time in Exchange Server 2016