Db Mail Storage?
Has anyone considered using MySQL for the email storage? Something like what www.dbmail.org is doing for the backend.
While I have only spent a few minutes browsing the architecture, it seems that maintaining integrity between MySql, Ldap, and the filesystem may be a big job. Removing the filesystem as the storage may be an advantage.
We actually think the work we've done to ensure LDAP, MySQL, and the file system stay sync'd well worth it. Storing messages as MIME files in the file system is the most natural place for them, and provides better caching for variable message sizes than any database could. The messages(files) are for the most part write once; read many. All the expensive searches are performed against the metadata in MySQL or the indexes of Lucene; both of which are designed for these types of queries. So we feel we've made solid choices in our design.