When you send an eCard, CorpNote uses your email address as the 'from ' and 'reply to' email address.
Your email administrator might have an email filter in place that is blocking incoming emails that say they're from a company email address, but are recognized as being sent from another email server. While this is a legitimate practice for third-party email services like CorpNote, it's also a trick that's used by spammers called "spoofing".
You will need to contact your email administrator and ask them to allow (white list) email from the CorpNote email server, using the following information.
CorpNote eCards are sent from:
IP Address: 126.96.36.199