Charter ISP Claims Outlook Generating STMP Errors of Too Many Recipients

[MJH 10]

I spent 2 hours with Charter.net and 2 hours researching this problem with no results.

The Outlook 2013 error message is:
Sending reported error (0x800CCC0F) The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP). The server responded: 452 4.1.1 nbto: 11 too many rcpts 10E2210

As I said, Charter was of no help--still can send with their web based email. I have verified all other email settings in Outlook 2013. I created a new profile that generated the same errors.

Can't really be a too-many recipients problem if I can send through there web mail interface. I can send from all my other non-Charter.net accounts.

I have never had this problem before. Started today with an email to 17 recipients. Now I can get the error if I simply try to send a single test email to myself.

I've spent 8 hours on this problem and still can't fix it==H E L P ? ? ?

Thanks in advance.

 

[MJH 10]

A bit more testing from additional research. I disabled my Avast virus software--still got the same errors. I disabled the Avast Add-in in Outlook 2013--still got the same errors.

I started Outlook 2013 in SAFE mode--appears to be running correctly, able to send test email in configuration and send email from account.

Attached is my Add-in Screen.

Suggestions? Please!