For dynamic content, it would be great to be able to set a fallback value (this is already set for the [Greeting] field). It would be nice to be able to create the field and determine that if it is left empty, the system sends the email with a blank value or a standard value. To prevent this from causing issues, it could be set up so that only when you enable this feature for the field, the system allows you to send out emails with a missing value in a dynamic field as well. An example of a use case would be a field designated for "praise" - The users can add a full sentence into this field (such as "I liked your article on XYZ"). If it is left empty, no harm is done - there will simply be one sentence less. Alternatively, the field could be set up with a standard sentence to fall back on when it is left empty, such as "I really like your blog".

This all gives users much more flexibility and personalization options, making bulk emailing liekly more successful. I've seen this type of functionality in various marketing automation systems as well.