General :: How To Eliminate Suggested Email Addresses In Yahoo Mail

I use the Yahoo mail android app (as well as gmail). When I create an email in the app and "click" in the "to" field and type a letter I get a whole raft of email address suggestions that are not in the contacts. I've looked in my phone contacts and they aren't there. I've looked at Yahoo mail settings and see nothing there. I've gone to the desktop Yahoo mail an tried looking in contacts there and they don't show up. Many of these are addresses of people that I recognize and have probably either sent or received an email from them but certainly never saved them as a contact. I tried long pressing on the suggested address and it highlights it but no options are given. It doesn't happen in my gmail. I've gone to URL...contacts and they don't show up there. I know I should just switch to gmail only but this is an old address that I want to keep active. I have a Moto X with Kitkat. This has followed me from phone to phone.