This looks harmless enough but, if you click on the link, you’ll let in a can of worms.
If you didn’t expect this and/or you don’t know the sender, delete it.
It is better to delete one legitimate e-mail then to open one that will destroy your system.
finjan did a nice job in warning me that the link wasn’t something I wanted to see.
But you aren’t sending me email with a link to an ecard greeting which displays the IP not a domain name. It is the addition of an IP and not the IP in isolation.
Nearly any legit greetings service will, in that notification, give you a “real” name as to who sent the card, typically taken from how the card was signed by the sender. Anonymous “classmate”, “family member”, etc., is usually one more warning sign.