Hi annietah,
We appreciate you responding to us and giving us an update.
We are glad to know that some of your emails are coming through, If the email status is "sent" it means that the email was sent successfully. However, on the invoice that did not come through, could you please check that the form you are using, e.g., the invoice templates, does not contain a special character in the name? You can check out this Help Article: Email Troubleshooting, for more information on checking emails.
If you still need further assistance, do not hesitate to contact us again or create a new post. We are happy to help.
If my response has answered your enquiry, please click "Accept as Solution" to assist other users find this information.
Kind Regards,
Cel