My name is***** am sorry to hear that you are having this issue.
I will be glad to assist you with this.
Try these steps please.
If your Yahoo Mail settings are corrupt in iOS Mail (the "Server Unavailable" error), the only way to fix it is to remove and re-add Yahoo Mail.
Remove Yahoo Mail from your iOS device's native email app. Here's how.
- Tap Settings | Mail, Contacts, Calendars.
- Tap the Yahoo Mail account you want to remove.
- Tap Delete Account.
- Tap Delete Account again to confirm.
Then readd and Make sure your settings are correctly configured.
- Tap the Settings app.
- Tap Mail, Contacts, Calendars.
- Tap your Yahoo Mail account.
- Tap Account, at the top.
- Re-enter your full email address and account password.
- Tap Done.
If your info matches, checks will appear and you'll return to the previous screen. If not, you'll need to use a computer to verify your login details.
Let me know if this does not work and we can try another solution.
Please reply and let me know if you need any other assistance,
Also, please take a moment to rate my service by choosing one of the stars at the top then click submit.