If you are sending invoices to your customers from your iOS device and each email is sending multiple times, this is likely happening because your email account was set up on your iOS device in the mail app under the section "Other." All emails should be set up under their specific type (iCloud, Microsoft Exchange, Google, Yahoo, Aol, Outlook), rather than through "Other."

First, please make sure your Invoice2go app is running on the latest version. You can check this on either the iOS App Store.

If you are still having email issues, please follow the troubleshooting steps in this article to resolve the issue.

iOS 

1. Go to your iOS device's Settings app
2. Tap Mail
3. Tap Accounts
4. Select the email account that is sending duplicates
5. Tap Delete Account
6. Confirm that you want to delete email from your device
7. Under the Accounts sections, tap Add Account
8. Tap the correct email type for account (Google, Yahoo, Aol, etc.)
9. Enter your email and password credentials
10. Tap Yes to let the default iOS mail app have access to your email account
11. Tap Save
12. Under the Accounts section, tap Fetch New Data
13. Toggle on Push 
14. Make sure Fetch schedule is set to anything but Manually