How can I change the email address in Zoho Books from which invoices are sent to my clients?

You can change your Zoho Books mail address by following these steps,

• Click on Gear icon on the top right corner and select Organization Profile.
• Click on Configure Emails next to Primary Contact. Click on the pencil icon to edit and specify a different email address for the primary contact and save changes.

• If you have multiple email addresses for an organization, please select Mark as Primary against the email ID of your choice.
• Verify this process by opening the confirmation mail sent to the mail address you’ve specified.
• You can now choose to send invoices to your clients via this email address as well by selecting it from the drop-down.