Ben,
I can't vouch for whether this meets AwareIM specs, but I know it works.
I acquired it from Powerm & got it up and running today in my Mandrill account.
You simply have to load six JAR files to your AwareIM/Tomcat/lib directory -- and don't forget to close your Control Panel & re-start AwareIM. I didn't have any prior experience with plug-ins so I banged my head against the wall for a couple of hours until I figured that out. You just need to add a few BOs, processes, and a service to your BSV and it works well.
On the Mandrill side, you have to register API keys and set up webhooks.