Q: Cannot stop tone for incoming mail on iphone 4.

Hello Weitbrecht,

It sounds like you do not want to have a tone associated with getting a new mail in the Mail app. Start by going here:

To change sound settings: Go to Settings > Sounds.

 

iOS: Understanding sounds, ringtones, and alerts

http://support.apple.com/kb/HT5800

The very first Alert Tone underneath Vibration is None. Select this to remove the alert tone for the Mail app.

Thank you for using Apple Support Communities.

Regards,

Sterling

Thank you for the update.

I would next try closing all the open apps on the phone:

iOS: Force an app to close

http://support.apple.com/kb/ht5137

Double-click the Home button.

Swipe left or right until you have located the app you wish to close.

Swipe the app up to close it.

When you have done that and restart the phone and test the issue again by setting the tone to None again:

iOS: Turning off and on (restarting) and resetting

http://support.apple.com/kb/ht1430

Deleting pre installed Tones and Alerts is not a function of the iOS. I would next try backing up your phone with the following article:

iOS: How to back up and restore your content

http://support.apple.com/kb/HT1766

And restore it from your backup with the steps in this article specifically to delete the orignial installation of iOS and install the latest copy fresh:

Use iTunes to restore your iOS device to factory settings

http://support.apple.com/kb/ht1414

When iOS was installed again during the set up process it prompts you to enter a new passcode so it would be what you entered when you just set it up again. If you do not remember it, or it was entered incorrectly you can reset it with this article:

iOS: Forgotten passcode or device disabled after entering wrong passcode

http://support.apple.com/kb/ht1212

It would have been step 11 from the article named:

iPhone, iPad, iPod touch: How to get started

http://support.apple.com/kb/ht4053

1. You should choose a passcode for your device. If you don't need a passcode, tap Don't Add Passcode.
   • On iPhone 5s, if you choose to use Touch ID, you must enter a passcode.
   • To make sure you did not make a mistake, you need to enter your passcode twice.
   • If you chose a commonly used passcode, you will be asked to choose a more secure one.
   • If you need to use a complex passcode, you can set in Settings > General > Passcode after completing this assistant.
     

I had another suggestion. Try Restoring the device 1 last time as new, not from a back up and test the tone. If that does not resolve the issue, then thank you for using the Apple Support Community. Due to the nature of your issue you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action.

Excellent! Glad to know the issue is resolved