External Source: http://blogs.gartner.com/bill-pray/2010/07/15/really-what-does-e-mail-cost/

When determining e-mail costs, it is important to look beyond the licensing costs and to also use, at the least, a three year average to get the best grasp on what it really costs.

Costs should include not only the e-mail licensing, but add-ons, mobile, perimeter services, archiving, and migration costs if you are considering a new e-mail solution.

So, here are two examples of large enterprise’s and their costs – remember your mileage may vary:

A large financial institution with 35,000 plus mailboxes on 60 plus servers (also significant regulatory and compliance requirements) -

  • Mailbox costs = $116 per user per year
  • Archiving costs = $46 per user per year
  • Perimeter services costs = $31 per user per year
  • Total costs = $192 per user per year

A large energy enterprise with 36,000 plus mailboxes, using an older e-mail solution and infrastructure (that is under review for replacement), with some of the servers being hosted by third parties -

  • Mailbox costs = 73,5 € per user per year
  • Perimeter services costs = 3,5 € per user per year
  • Total costs =  77 € per user per year