Example email:
- I want bigger mailbox to handle bigger mails incoming and outgoing. Result: bigger mailbox.
- Then everyone else in the company gets bigger mailboxes. Result: bigger mailbox x1000.
- Also: bigger mail-server backups.
- Also: bigger desktop/user-profile backups, because Outlook duplicates all this info locally.
- Also: bigger storage needs for anything also interacting/duplication selected mail (like CRM, import services, whatever).
- Also: bigger backups needed for all those systems.
- Etc etc.
And IMO it's a perfectly valid claim.
Maybe storage "only" costs $0.1 per 100GB in isolation (or whatever), but for a full company with all systems involved, in aggregate it quickly it may exceed 1000x that.