If your email design contains Dynamic Elements, and you send yourself a test message, you may notice they do not populate. If your email design contains "[GUEST_FIRST] [GUEST_LAST]," you'll see "Dear {First Name Placement} {Last Name Placement} in the test message. If you're email is an Invitation and contains "[INVITE_LINK]", you'll notice the link does not work.
Why is this? Dynamic Elements pull information about the guest from the Guest List, in order to populate the correct information for that guest. Tests are not connected to the Guest List, thus cannot populate the Dynamic Element information within the email. We use placeholders for test messages, instead.
To see the email exactly as guests will, add yourself to the Guest List, then send an Invitation or Send a Message. If using Send Group Message, create an Address Book group with your email address (and the email address of any other testers), then send the Group Message to that Address Book group.