In-house email systems require a lot of high-tech staff hours. The investment in system administrators and IT experts required to manage the workings of an email system can be a large financial burden. Outsourcing firms dedicated to email management can manage thousands of users simultaneously. They have dedicated staff to deal with any problems that may arise (and they often will arise at the least opportune time), and all of these services will be provided for a set contracting fee that is determined ahead of time and remains fixed no matter how big the problem turns out to be. This simply isn't the case with in-house technical staff running an in-house system.
 
 
