I use Rapportive and Mailchimp extensively.

It would be nice to be able to have a small icon show up next to the name of the sender in the Inbox if certain criteria is met. For example, is the send is on a Mailchimp list, show a Mailchimp icon indicating this.

Also, the ability to apply a label to messages that ARE in a Mailchimp list, or ARE NOT in a mailchimp list, would be good to be able to find senders which are not a part of your CRM/Social network, make some e-mail introductions, etc., without having to weed through each message, click on each one, and check whether or not they are in your Mailchimp list, or not.

Thoughts?