Outlook Password Retries and CSF IP Blocks

If Outlook keeps trying an old or incorrect mailbox password, repeated failed sign-ins can trigger CSF/LFD login-failure protection. The firewall may then block the public IP address your device or office uses from reaching mail services. Outlook can continue showing connection errors even after the password is corrected until support removes the block or it expires.

Stop Outlook from retrying the old password

  1. Stop retrying the password. Confirm the current mailbox password by signing in to webmail, preferably from a network that is not blocked.
  2. Quit Outlook on every device using the mailbox on the affected network. Also pause other mail apps that may still have the old password saved.
  3. Update the password in Outlook. In classic Outlook for Windows, check File → Account Settings. If Outlook still submits the old password, close it and open Windows Credential Manager → Windows Credentials. Remove the saved entry for the mailbox or mail server, then reopen Outlook and enter the current password.
  4. Update the saved password on phones and other computers before reconnecting them. Another device retrying the old password can cause the block to return.

Request removal of the IP block

Mailbox users cannot remove a CSF block themselves. Contact StridX support and request removal of the mail access block. Include:

  • The public IP address of the network where Outlook was connecting when it was blocked. Find it while connected to that same network; an address shown as 192.168.x.x or 10.x.x.x is a private local address, not the public IP. If you use a VPN, provide the VPN network’s public IP.
  • The affected mailbox address and domain.
  • The approximate time the block occurred, including your time zone, and the Outlook error message.

If you are on an office network, ask your IT administrator for the public IP. If your public IP has changed since the block, provide the current IP and the approximate time of the failed attempts so support can investigate the previous address. Do not send your password or one-time codes.

Support will verify the block and remove the relevant IP entry. A public IP may be shared by other users on the same home, office, or VPN network, so tell support if multiple people are affected.

After support removes the block

Reconnect one device first and test sending and receiving. If the IP is blocked again, stop Outlook and other mail apps and contact support with the new time and error. A device may still be retrying a saved incorrect password.

If webmail works but Outlook does not, see Outlook connection troubleshooting.