Distribution list causes email program to shut done when send is pushed

So I have a rather extensive email list. I have 11 distribution groups numbered 1-11. They’ve always worked fine until recently. I always send in BCC but as soon as I click on send for group 1, 8,9,and 10 the email program shuts down and restarts after data checks. I’ve deleted the groups in question and re-created them and still program shuts down. I’ve even changed names of the group and still, shutdown. Anyone have any idea whats going on and what the fix may be. Please and Thanks

Hi Peter,

Send me please an email to markosky@emclient.com.