outlook.com email Command error. 12

Question

What is the cause of the email Command error 12?

This appears to be a random error that occurs in 3rd party email software in regards to microsoft email accounts - that generally self-resolves very quickly.

Answer 1

Hello Mike and Flo
Thanks for reaching out to the Microsoft Q&A forum. 

Based on my research, there are a few factors that could explain why “command error 12” resolved itself when using a third‑party application: 

• Temporary rejection from the server: High server usage or a brief service interruption can cause IMAP commands to fail. Once the server load stabilizes, the request may succeed without any action from the user. 
• Throttling:  If a large number of IMAP commands are sent within a short time, the server’s throttling policy can activate. This policy protects the server by temporarily rejecting the requests. When the throttling period ends, the connection can restore normally. 
• Automatic retry logic from the client app:  Most third‑party applications include built‑in retry logic. When a temporary failure occurs, the app automatically retries the request until it succeeds. This often appears as the issue resolving itself. 

To help me better understand your case and tailor my research more accurately, could you please provide more details on the following points? 

• Which third‑party application are you referring to? 
• Since you mentioned outlook.com, could you explain how it is involved? For example, are you sending an email from an IMAP account to an Outlook.com recipient? 
• You also added the Exchange Server tag. May I clarify whether the message is being sent from an Exchange Server? If so, which version of Exchange Server are you using? 

I hope this provides additional clarity, and I look forward to hearing from you soon. 

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Answer 2

The context provided does not specifically mention an "email Command error 12" or its causes. It appears that this error may be related to third-party email software interacting with Microsoft email accounts, but without specific documentation or details regarding this error, I cannot provide a definitive cause or resolution.

For troubleshooting email issues with Microsoft accounts, you may want to check general email configuration settings or consult the support documentation of the third-party email software you are using.

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References:

• Email non-delivery reports and SMTP errors in Exchange Online
• Sending mail from Outlook results in error 0x800ccc80