My Outlook keeps sending duplicate emails and also automatically moves certain incoming emails into Trash

Andrew Chidester 0 Reputation points
2026-09-10T17:06:10.7+00:00

My Outlook keeps sending duplicate emails and also automatically moves certain incoming emails into Trash. Please help me fix these problems.

Outlook | Windows | Classic Outlook for Windows | For business
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  1. Chris-D 1,180 Reputation points Independent Advisor
    2026-09-10T17:31:34.7566667+00:00

    Hi Andrew,

    Thank you for sharing the details of your situation.  

    Based on your descriptions, here are some steps you can try: 

    1/ Check whether the emails are actually being sent twice (If you are using an IMAP account)

    • Please send a test email to another address and confirm whether the recipient receives two copies or whether two copies appear only in your Sent Items folder. 
    • If duplicates appear only in Sent Items and you are using an IMAP account, the mail server and Outlook may both be saving a copy. Go to:  File > Account Settings > Account Settings > select the affected account > Change 
    • If available, select Don’t save copies of sent items, complete the setup, and restart Outlook.  

    2/ Review your Inbox rules 

    • Go to File > Manage Rules & Alerts and check whether any rule is configured to delete messages or move them to Deleted Items. Temporarily disable any suspicious rules and monitor whether the issue continues.  
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    3/ Check the Ignore Conversation setting 

    • The Ignore Conversation feature can automatically move current and future messages from a specific email thread to Deleted Items. 
    • Open the Deleted Items folder, select an affected conversation, and go to Home > Ignore > Stop Ignoring Conversation.  
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    4/ Test Outlook in Safe Mode 

    • Close Outlook, press Windows + R, enter outlook.exe /safe, and select OK. Then test whether the issue still occurs. 
    • If the problem does not occur in Safe Mode, an Outlook add-in may be responsible. Go to File > Options > Add-ins > Manage COM Add-ins > Go, temporarily disable the add-ins, and re-enable them one at a time to identify the affected add-in.  
    • Also check the mailbox through Outlook on the web. If the issue occurs there as well, it may be related to a mailbox rule, setting, or another connected device rather than classic Outlook alone. 

    If the issue persists, please let me know: 

    • Whether recipients actually receive duplicate emails or duplicates appear only in Sent Items. 
    • Whether the same issue occurs in Outlook on the web. 
    • Whether the issue continues in Safe Mode. 
    • The account type, such as Microsoft 365, Outlook.com, Gmail, or another IMAP provider. 
    • Any relevant screenshots, if available. 

    I hope this information is helpful. Should you have any further questions or need additional assistance, please feel free to share them in the comment below. I'm very happy to help.  

    I look forward to hearing your thoughts on this. 

    If the answer is helpful, please click 'Yes' and kindly upvote it.

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  2. AI answer

    2026-09-10T17:06:26.3266667+00:00

    For the duplicate sent emails in classic Outlook for Windows with an IMAP account, the supported workaround is to stop Outlook from saving its own copy of sent items:

    1. In Outlook, go to File > Account Settings > Account Settings.
    2. Select the IMAP account, then choose Change.
    3. Select Don't save copies of sent items.
    4. Select Next, then Done.

    This works around cases where the mail server already creates a Sent Items copy and Outlook uploads another one, which causes duplicates. The unread status on one copy is also controlled by the server.

    For incoming mail being moved automatically to Junk or Unwanted, one documented cause is a Samsung mobile device using the default mail app with entries under Spam addresses. In that case:

    1. On the Samsung device, open the email app.
    2. Press Menu > Settings > General Settings.
    3. Open Spam addresses.
    4. Remove any addresses or domains that should not be there, such as the corporate domain.

    For Outlook.com-style junk filtering, also check whether senders or domains were blocked:

    1. Select Settings.
    2. Go to Mail > Junk email.
    3. Review Blocked senders and domains and remove any address or domain that should not be blocked.

    If mail flow problems continue after these checks, run the classic Outlook troubleshooters. If that does not help, contact support.

    AI-generated content may be incorrect. Read our transparency notes for more information.

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