Forwarding causes problems because of the security constraints that Adobe places on their email.

If a Cornell user forwards email to services such as Gmail, AOL, or Yahoo, these messages currently end up in the Spam folder. (This does not happen with Cornell's Google Workspace for Students or Google Workspace for Faculty and Staff, since Cornell is able to instruct that service to accept these emails.) If the user to whom you are sending might forward their email, ask them to add adobesign@adobesign.com to their address book, or to check their Spam folders for the message.