When I am sending forms to customers such as invoices, they receive 2 copies of the same email to the same email address as on the contact details,How do I correct this?

Hello ianbell-108, Welcome to the Community. Just a few questions so we can help with this, when you go to sales>customers>edit in the top right. Is the email address for the customer in there only once? If you go to the invoice itself and on the black banner select audit history click on the date sent is that date there twice? Within the main invoice on the bottom left does it show as sending twice? Thanks