I cant seem to have my emails updated!

I have email that is pushed to all three Apple products I own (iPhone, iPad, MacBook). The emails all show up on all three devices without fail. The problem is that when I read, move, or delete an email on one product, it does NOT affect that same email on the other products. For example, if I read an email on my iPhone and then delete it, that same email remains in my INBOX on my iPad and Macbook. I have to go on each device and either delete or move each email. I know that it did not used to be this way. It started a few days ago. How can I fix it so that if I read, delete, or move an email on any of my devices, that same task is completed on both of my other devices?

Thanks.