BCC: GROUP EMAILS NOT BEING RECEIVED

Can you explain the remedy? I'm not seeing on this forum how you fixed the problem. 
I send 4 groups of messages daily to congregation.  The groups consist of anywhere from 30 -50 recipients.  The messages seem to send but not received.  I tried setting up test group of 5 recipients and messages were not received.  There is no error message to say messages did not send.  I am now sending messages using my groups to TO:  which I do not like because it sends individual emails but at least they are being received.   I desparately need help in resolving, since creating test group did not work.  This problem started a month+ ago all of a sudden.  I was told that maybe being blocked due to thinking emails were spam but I've been sending emails like this over 5+ years and now this.  I need a resolution. I am sure my recipients are not happy seeing their email addresses going to everyone.

You cannot get a LIVE BODY to speak to and when you go on chat assist, it is frustrating when it comes back asking for a simplier explanation or few words.  You both both it comes back again with a list of comcast prefer references.    HELPPPPPPPPPPPPPPP!!!