With Akonadi most operations are running behind the scenes, carried out by background helper processes called Akonadi Agents.
While we do have respective progress monitoring in KMail2, users will eventually take advantage of fact that they are no longer tied to specific applications. At which point they might want to be able to check on the status of these background processes without launching some front end applications.
It is quite normal, in Free Software initiatives, for people to come in, help out, become proficient, maybe even moderately famous, then eventually move on or drop out. Often life gets in the way, parenting, post entry level jobs and growing responsibilities reduce the available time something fierce and once one is no longer really familiar with the code base, it becomes hard to make an effective contribution in those short time and motivation windows that open up. Somewhat ironically, since a large part of my job revolves around KDEPIM, this is very true for me as well.
Those who have read my previous blog entry will remember that I have been working on a way to directly operate on a mixed tree storage layout.
"Mixed tree" means that the mail folder tree (hence "tree") consists of Maildir and MBox folders nested in each other in any combination, e.g. Maildir inside Maildir, MBox inside Maildir, Maildir inside MBox.
Since this is highly KMail specific, it should probably be called "KMail tree" or "KMail mail directory", but there is always room for improvement, especially with naming.