More engaging email preview for summary/digest

I think that the email preview of the summary/digest email at the moment is rather dry and repetive:

I don’t need to see the forum title again, or “since your last visit on September 26”, for example.

I’ve seen that other forum summary emails lead with the title of their most popular post. What do you think about the idea of making the email preview or subject line be the title of the first popular post, instead?