2.Personal vs Younify email
When you created an Younify account you entered a personal email. This is the email you must use to login to Younify.
The email @ydocs.io should be used only with your suppliers by asking them to send your new invoices by email to @ydocs.io. This email cannot be used to login to your Younify account. However, your supplier may ask you to use this email to login to his online platform because you requested them to modify your email there.
You can request your suppliers to send you the new invoices @ydocs.io by changing the email address into your supplier online account (more details here), by creating a new online account with your supplier using the Younify email, by telephone, via email or any other method approved by your supplier.
Access to your @ydocs.io is done via your personal email. All messages received @ydocs.io are forwarded to your personal email. Just access your personal email to access all messages received @ydocs.io.