Hi Yumiko - The emails are sent based on the email-ID configured for each customer. When an invoice is created, the email ID is copied from the customer master to invoices.
If you do not want a customer to receive an email, you can configure an internal email ID under that customer's name - for starters
If invoices are being sent to wrong customers:
1. Please export your customer data in an excel and check if there was an error in mapping email ID with individual customers. Many times due to copy pasting operations while implementation, such data pasting errors can happen. You may not be able to verify them all because of the size of the data, make sure to check customers who have repeatedly received wrong invoices in the past and also a few others at random
2. After all email IDs look to be in place: Question: What % of your invoices have different Bill-To & Sell-To customer ID?
To troubleshoot, I would suggest use your Sandbox Environment, possibly create a copy of your existing company. Make sure your Email Accounts setup is complete in the Sandbox Environment. For more details, have a look at this link https://learn.microsoft.com/en-us/dynamics365/business-central/admin-how-setup-email
Configure 2 customers, with 2 internal/team email ID's. Create invoices for each of the customers individually, first when each invoice has Bill-To equal to Sell-To, then other 2 invoices where Sell-To & Bill-To are different (if you ever have that as a use case). Now trigger your Emailing Batch, like you've done above and see which team member receives what email in their inboxes. This will give you an idea of how email ID's are prioritized when you have different Sell-To & Bill-To scenarios
3. For your current scene, where incorrect invoices have been sent to customers : Open an incorrectly sent invoice, click on the top right question mark on the black ribbon & click "Help & Support". A page will open, press "Inspect pages & data", a gray side form will pop-up. Now there will be a small magnifying- glass button on the side form. Click that and enter keywords like Email, E-Mail, etc and see which keywords give you the correct result. Here you will come to know which email ID have these invoices been sent to
Note that emailing of invoices works based on email IDs configured. Its just a matter of which customer (from Bill-To/Sell-To receives it)
Feel free to write another question if need be
**Please mark this as a suggested answer, if it helped you**
