"Until you start dealing with being blacklisted because of spammers, maintaining relays, incoming spam filters (which are never as good as Google, et al), hardware maintenance and replacment (or expansion if you're doing it using your own internal cloud infrastructure) etc. And that's before you start looking at ensuring it stays secure, patching, minimising downtime etc."
I have been maintaining my own mail server for my business and personal use for around 10 years, I also host email for a few non profits and friends at least once every 6 months I have to go through the process of trawling the logs, working out whats happened and why we have been blacklisted and groveling to the various places maintaining the black lists (interesting point SpamCannibal seems entirely automated and I have not once managed to speak to a human) on a few occasions I have had to buy a new IP address to send mail from because I have not been able to have our IP removed from the blacklist.
Its a pain in the arse and its making me think more and more that Ill just pay Microsoft for office 365 and let them worry about these things!
Biting the hand that feeds IT
