Any ideas on this issue, When I am reading an email, on my phone, in Yahoo mail from let's say T-mobile and I have to log in and they send a code to my email address, yahoo. But I am already in my email and can't get to the code other than going to my pc and logging into yahoo from there.... Is there a way to get to the code from the mobile phone?

It all depends on how you have your verification set up in Yahoo mail. If you want them to send a code to your phone number, then you will have to set that up in your Yahoo account.