When you send emails through Kennel Connection, this is the process:
When you hit Send or it's time to send automatic emails, KC logs into your email provider's server. Once your login information has been authenticated, KC sends all emails to your provider at once. That's all it does. It's up to your provider to send the emails to your clients.
The only job KC has is to hold your email settings and make contact with your provider's service. It's up to your computer and email provider to keep that connection open for the emails to be sent. This error means that something is closing the connection between KC and the provider's server before KC can send the emails.
Make sure your antivirus is set to not scan KC or outgoing emails. Click here for instructions. You may also need to disable the antivirus completely and test again. If it works, then you'll need to work with the antivirus company to fix the issue.
Next, see if Windows did any updates recently, or if any software been installed/uninstalled recently. Something or some setting on your computer can cause this.
If you've ruled out everything on your computer, you will need to contact your email provider to see if they can determine why this connection is being cut.