Mail is in the genes of the organisation I work for. To this day it still has one of the largest Hosted Exchange platforms in the country and some of the very best Exchange engineers in the business. I find these Exchange engineers - meaning those dedicated to Exchange management on a day to day basis, some of the most deeply passionate people I have met in all of IT. They love what they do - absolutely mad for it. I encourage anyone to talk to them about DAG's or SMTP Configuration, or TNEF, or Delegate Permissions, or Mailbox Protocols, or SmartHost integration, or Replay Queues, or RAID, or Jetstress or least cost routing paths.