I am experiencing the issue of walking into a new company as a sysadmin and no one has looked after their exchange for a long time.
Because of that there is a mailbox (Lets call it Mailer) that is around 1TB now and gets around 9000 e-mails a day.
It is the only mailbox in a database (edb) but due to its size I am struggling to do anything with it.
I have tried PowerShell export to PST commands (New-MailboxExportRequest), even running it in a months cut off it takes up to 5 days to run (Running PowerShell on a local PC as when I did it in the Exchange server it became unresponsive)
While the Export command is running, we are getting a heap of "E-mail delayed" notifications coming out of that account to customers (Really bad thing).
So my new theory is, create a new mail database, in that create a new mailbox. Then somehow tell my mail account (Lets call it Mailer) to use that mailbox instead of the huge one.
The only issue is I have no idea how to achieve this, or if it is even possible. Any help would be great.