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For better research, please provide more details about this case:
Do other users in the organization have the same problem?
What is your account type (POP/IMAP/Exchange)?
What is your Outlook client version? Please make sure to update to the latest version.
There are many reasons for this problem, try the following possible solutions:
- Use OWA to send an email to see if the problem persists.
- Please try to run “outlook /safe” in the Run to start outlook as safe mode, to avoid interference from third-party Add-ins.
- Repair Outlook program.
- If the above methods don't help, try creating a new profile to check if there are any differences.
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