There is a hidden cost to this though. Running your own email server, or even having a lesser-known company manage your email server, can cause your emails to be sent to spam without any action on your part. You aren't notified when your email goes to a spam folder, so you always have to worry that the recipient of your emails didn't receive the email, even if you only ever send legitimate emails. If you stay on top of all the best-practices for running your own mail server, your hidden cost is the mind-share that that takes.