Can't receive or send emails in Outlook

Because the account was recently hacked and now can’t send or receive mail, both security recovery and Outlook.com-specific checks are needed.

1. Confirm the account is not blocked and storage is not full

• Go to Outlook.com in a browser and sign in.
• If the account is temporarily blocked due to unusual activity, follow the prompts or use the Sign-in Helper from Unblock my Outlook.com account.
• Check mailbox and cloud storage; if either Outlook.com mailbox or OneDrive storage is full, sending and receiving email will stop. Free up space if needed.

2. Complete hacked-account recovery steps Since the account was hacked, follow the full guidance in How to recover a hacked or compromised Microsoft account:

• Ensure the PC is clean: run a full scan with Windows Defender (already done, but confirm it’s fully up to date and has completed a full scan).
• Change or reset the password again from a clean device using the change your password or reset your password links.
• Check account settings that attackers often modify:
  • Outlook.com connected accounts
  • Forwarding settings
  • Automatic replies Remove any unknown addresses or rules.

3. Check Outlook.com mail behavior If sign-in works and the account is unblocked and not full, but mail still doesn’t flow:

• Verify that messages are not being hidden:
  • Check Other tab, Junk Email folder, and Junk Email settings.
  • Remove or adjust any rules or filters that might move or delete messages.
• If only certain senders can’t reach the mailbox, ask them to review Sender Support in Outlook.com.
• If using Outlook apps or other mail clients, confirm they support modern authentication and IMAP as required; if IMAP/POP are enabled and causing issues, consider disabling them per POP, IMAP, and SMTP settings for Outlook.com.

4. If the account still doesn’t send/receive

• If messages are bouncing with errors like “The recipient server did not accept our requests to connect,” review and, if needed, update the primary email address or alias using Add or remove an email alias in Outlook.com.
• If none of the above resolves the issue, use the Outlook.com interactive troubleshooter from Can’t send or receive email in Outlook.com, or use the Help menu in Outlook.com and choose Still need help? to reach support (sign-in required). If sign-in is not possible, use the dedicated “can’t sign in” link in that article.

5. If control of the account is still in doubt

• If there is any sign that the attacker still has access (unexpected rules, forwarding, or sign-ins), repeat the hacked-account recovery steps and consider using the account recovery form and support options described in the Q&A guidance:
  • Follow How to recover a hacked or compromised Microsoft account end-to-end.
  • If recovery via the web form fails and security info was changed by the attacker, there may be no additional method to regain access beyond the official recovery flow.

References:

• Can't send or receive email in Outlook.com
• Unblock my Outlook.com account
• How to recover a hacked or compromised Microsoft account
• Hacked email and I cannot receive any email on the hacked account - Microsoft Q&A
• My account got hacked - Microsoft Q&A
• My account got hacked. - Microsoft Q&A
• Hacker set up continuous draft ransomware email - Microsoft Q&A
• How do I send an email to Microsoft about my account being hacked and taken over by <removed> ? - Microsoft Q&A