Thank you for your question and for reaching out with your question today.
This error message is normally related to an issue with your Outlook installation or email account configuration. You should first of all check for Windows and Office updates and apply any outstanding updates. If this does not resolve the issue, you should try removing and re-adding your email account to Outlook. If Outlook doesn't;t allow you to do this due to the issues it's having, you will need to remove Outlook from your computer and reinstall it.
If this does not resolve the issue, please try the following:
Disable any proxy servers or VPNs.
Disable any third party antivirus
Change your SMPT Port to 26
Change to TLS on port 587
Check your firewall
If all else fails, you may need to perform a complete system restore.
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