Some things to check if an email sent never arrives…
Is the email being sent from and to domains on the same server?
If you are using an external email provider (e.g. gmail) ensure that email service is not turned on for the destination domain on your server. If it is then the email will never be sent because the your form handles messages as if your website and mail servers are both hosted at the same place. As a result, your local mail never leaves your web host.
Did email arrive at a gsuite account?
https://support.google.com/a/answer/55299?hl=en
As a G Suite administrator, you can find missing messages using Email Log Search. If a message was delivered to Google’s server, the tool will let you know of its whereabouts for up to 30 days.
- In your Google Admin console (at admin.google.com)…
- Go to Reports > Audit > Email log search.
- Next to Date, select a date range from the list.
- In the search fields, enter any information you have and click Search.
- Under Subject (or Message ID), click any of the subjects to see message details and delivery status.
- If you don’t see anything about the message, it wasn’t delivered to Google’s servers.
Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.