The Google Forms addon lets you set up email notifications when someone submits your Google Form. Internally, when a form is submitted, a trigger is invoked that uses the Gmail API to sends email messages on your behalf. The trigger works in real time and the notifications are generated instantly.
If you are not receiving email notifications, here are some troubleshooting tips.
1. Check you Email Folders
Check the Sent Items folder of your Gmail account. A copy of all email notifications are automatically saved in your Gmail mailbox.
Also check the Spam folder of the recipient’s mailbox. Sometimes an email may get marked as junk due to the message content.
2. Is your Email Quota Over?
Free users can send up to 50 emails per day while premium Gmail users can send up to 400 email recipients. Google Apps for Work and Google Apps for Education users can send up to 1500 email recipients with the premium edition [Upgrade to Premium].
The daily email limit is email recipients per day and not email messages per day. Thus if your are emailing a single form response to 2 people, it will reduce your daily quota by 2. In other words, you can send 25 free responses per day if each response is sent to 2 people.
Google will automatically reset your daily email limit at midnight Pacific Time.
3. Is Gmail Enabled for your Google Apps domain
If you are Google Apps / G Suite user, your domain admin needs to enable the Gmail service for you to send email messages through any of the Google Addons.
See this link for steps on how to enable the Gmail service for users in your organization.
4. Are you Getting Multiple Email Notifications
It is likely that your Google Form is shared with multiple people. If they too have configured the Email Notifications add-on, the emails will go out from their email account resulting in duplicate emails.
To rectify the issue, open the Google Form, go to add-ons > Email Notifications, Troubleshooting and choose Disable Notifications. You need to do this under the email account that is sending the duplicate email notification.
5. Restart Google Form Notifications
If you have changed your Google account password, or if you have revoked access to the addon under your Google Account settings, or if your Google Apps (G Suite) admin has changed any security settings, you may have to re-authorize the addon to get it working again.
Open the Google Form, go to Addons > Email Notifications > Troubleshoot and choose Restart. This will likely resume the notifications when all else has failed.
If the issue is not resolved, please contact technical support.