In the Melio app, you don’t need to add an email address before you pay a new vendor. It’s helpful if you add an email when setting up a new vendor as that way, they'll receive an email every time a payment is made.
Note: Adding an email address for an existing vendor.
This can only be done from melio.com.
This article will show you more detail about what your vendor will receive when you make a payment via Melio.