Do you mean that the outbound email from one of your users will show in the deleted folder of other mail server?
To narrow down this, I want to confirm with you:
- What is the mail server that you used?
- Whether other users on your mail server have this issue?
If only this user has this issue, it means this user may be blocked by the recipient mail server.
If this issue occurs on all your mailboxes. I would check with your whether this issue occurs when you send emails to other mail server?
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