Mail app on iPhone closes after a few seconds

Hello lorenaga,

It sounds like there's an issue with the Mail app quitting unexpectedly on your iPhone 4s. If you haven't already, take a look at the article below and try running through the general troubleshooting tips that it provides.

Get help with Mail on iPhone, iPad, and iPod touch - Apple Support

Try these steps first

1. Make sure that you're connected to the Internet
2. Verify your user name or password. Sign in to your email provider’s website and make sure that your email account is active.
3. Check your email settings. If the settings are unavailable, contact your email provider.
4. Close and reopen Mail.
5. Restart your iOS device.

If you can add an email account to your iPhone, remove the affected email account from your device:

1. Tap Settings > Mail, Contacts, Calendars.
2. Tap the email account.
3. Tap Delete Account.
4. Add your account again.

If you have a POP email account, make sure that your email settings match your device.

1. Tap Settings > Mail, Contacts, Calendars.
2. Tap the email account.
3. Make sure that the information matches what you see on your device.

Cheers.