The school district I taught in
Opted to NOT provide student email accounts, for several reasons. (This was in 2000.)
* Hardware costs. With 25k+ students in the district, they would need a dedicated email server with a minimum of 100 GB of storage, 400 GB if they set the mailbox size to 100 MB.
* Admin costs. They estimated they would need four additional FTE to manage that many mail users: two on the help desk, and two in mail admin.
* Politics. The district was fighting to get a bond issue passed for a new high school, a new middle school, four new elementary schools, and a new football stadium. The board didn't want to lose that in a urinating competition over student email.