Mysql S3 Storage Plug-in for hugely scalable message store.
Mark Atward has written a MySQL S3 Storage plug-in. It hooks MySQL to the Amazon s3 storage backend. I was thinking it could maybe be used as a addon to dbmails mysql back-end to make for a hugely scalable storage solution.
Mark suggests a balance between local storage for meta-data speed and BLOBs on S3 for scalable fault tolerant storage.