So after you've gone through all of this, your parents will continue to use Yahoo. They likely don't pay Yahoo anything, and Yahoo doesn't feel obligated to do

So after you've gone through all of this, your parents will continue to use Yahoo. They likely don't pay Yahoo anything, and Yahoo doesn't feel obligated to do anything other than provide an email address that works most of the time. This is exactly the conversation I have with clients in this sort of situation: "You shouldn't be using Yahoo, or any other free email service, for your business email. Even if we could solve this problem now, you're going to have another problem later on. We need to set you up with a proper, professional email address, you will have to send out a short update to your contacts announcing the new email address, you'll have to update your website and any other business materials, and for a while, you'll have to forward all of your Yahoo mail to your new email address. I know this sounds expensive and sounds like a lot to have to do right now, and it is, but I don't provide Yahoo support for free, and you're better off getting this fixed now rather than putting it off and having to do it another day anyway. I'll be happy to help you with all of this." If somebody, whether family or client or otherwise, uses Yahoo or Gmail or Hotmail (or outlook.com or whatever the heck it is now), I'll make one good faith attempt to resolve their trouble, and then after that I simply don't care anymore. They're using a stupid service, and that's their problem, not mine, and I'm not going to grow another gray hair over it.