Users often complain about the issues they have to face while using Yahoo on iPhone. One of the common issues that users have to encounter is Yahoo email not working on iphone. The immediate solution to this problem is to check the internet connection as this could be one reason for the issue. This issue can also arise if the Cellular data for your Mail App has been disabled. Hence enable the Cellular data, and you can also delete and re-add Yahoo mail to iPhone to get the issue fixed.