If an eCard or email newsletter is sent to an email address that is no longer in use, then you will get an email 'bounce back' at the email address you are using for your account. This works just like an email that you send to an inactive email address via regular email.
The email address you use to sign into your CorpNote account is the email address that the bounce back will come to. It is also the email address that is used when someone replies to your business greeting cards, email newsletters, online invitations and online surveys.