Why do my incoming emails appear in sent items MS Outlook, and how should I solve this problem?

• Spam messages in your Sent folder usually indicate that a hacker has gained access to your email account and is using it to send spam to your address book contacts.
• To prevent this from happening again, you'll need to lock them out of your email account.
• Check your Junk Folder.
• Verify your Internet connection and Outlook Service.
• Determine if your Inbox is full
• Reset the Inbox Filter.
• Check the Blocked Users List
• Move Emails to a Different Folder.
• Clear Multiple Connected Accounts. Get Rid of Outlook Rules.

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