It is a very much useful mailing service in the world, I think.
i’m using this service for last two years but didnt observed any breakdown of the server a single time.
it is the fastest service for email and searching as well.
they provide a y-briefcase and a photo album to every Y-user as well.
i liked it because we have 6 MB space free for our email and 25 MB space for the briefcase and photoalbum each.
you must try this service as it is a unique in the world.