Welcome to Justanswer.com, my name is ***** ***** I will do my best to assist you.
There are several variations, causes, and solutions to this type of issue. I need to ask you some questions to narrow down what the exact issue is that you are having so we can resolve it.
Thank you in advance for your response.
Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.
Thank for getting back to me. 400 emails attempted to send per hr.. Thats quite a bit.
Who is your email provider that you are sending this mail through? gmail, aol, hotmail, yahoo, etc.
Also, who is your Internet service provider?
Good afternoon. Im not familiar with the videotron provider. I assume this is their webmail portal.
Can you log in to the webmail portal. And then, create a message and attempt to send it to the hr A group that you said had only five or six people.
If you log in directly to the webmail portal and try to send a group message using BCC. Will it let you end it from the portal?
This is a very important test, as this will tell us whether the issue is with Windows Live mail, or whether the issue is with your ISP blocking group mail. Once we know that answer, we will also know the solution. Let me know the results of this test when you can.