Not All Members Received Message through Member list-serv address

Hi,
This is Imelda of Bearcat Toastmasters #8020. Two days ago we experienced that our treasurer's message sent through the members-8020@toastmastersclubs.org has not been received by members. What could the problem be?
Thank you for any support you may extend to us.
Imelda

I reviewed our email logs, and I do see the dues renewal email that you sent out, but I not see anything being sent through our list server from Julie F's email address that is listed in Membership Management. Are you sure that she sent it to the correct email address? People sometimes drop an 's' from the email addresses...

BTW, it may interest you to know that I am a U of Cincinnati alumnus, BSChE (Graduated 1989 from the College of Engineering). I wish your club was around when I was there. Go Bearcats!