Where is the sent email from Zoho Books?

Where is the sent email from Zoho Books?

Hello,

We have the CRM, Zoho Books, Zoho Mail and other Zoho apps. When I send an email from Zoho Books, whether with an invoice, a payment reminder or payment received notice/thanks, it seems to disappear afterward. It's not in the Sent folder of my Zoho Mail, nor in the Contact record in the CRM, nor in Books. Where are the emails that we send from Books stored? And is there a way to easily see which payments received have had a thank-you email sent out?

Thanks and regards,
Dennelle