Why is one person on my email list getting double emails from me?She is only once on my address book yet receives double each time. What is going on and which end is at fault. How do I take care of this problem..

All other email accounts not with yahoo are working perfectly. We have checked all our internet setup and it’s fine! I am list owner to a yahoo group and a lot of the members are complaining about yahoo.management of their email accounts also. Trying to open my account can take up to 6 minutes. When will it be working properly?