People who are more than casually interested in computers should have at least some idea of what the underlying hardware is like. Otherwise the programs they write will be pretty weird. (Donald Knuth)
The idea that Bill Gates has appeared like a knight in shining armour to lead all customers out of a mire of technological chaos neatly ignores the fact that it was he, by peddling second rate technology, led them into it in the first place, and continues to do so today. (Douglas Adams)
When talking about Kerio MailServer I sometimes hear customers worried about the cost of maintenance and support. On the face of it, I have a simple answer: all support, both from me and from Kerio directly, is included in the subscription fees.
However, that obviously just covers asking questions - it doesn't cover the customers actual hands on time doing maintenance and support tasks. I can quote "hands-off" support contracts if desired, but I tend to discourage that because there really isn't a lot of work involved. That
statement can generally be applied to maintaining any in-house mailserver, from Sendmail on up through Kerio, Exchange or anything else. Ordinarily, there just isn't that much to do: add and remove users, change passwords now and then, investigate mail delivery problems, perform upgrades... there really isn't much else. Of course there are the types of things that can affect any server: running out of disk space, hardware failure, virus infection... and there are the problems that are unique to email, whether hosted in-house or not: spam, virus transmission, archiving needs.
Did I forget anything? If so, please remind me in the comments.
Undoubtedly the most maintenance originates with Outlook and Outlook Express. Outlook Express is particularly fragile. These problems have nothing to do with Kerio specifically; when running as a POP client with mailboxes stored on the client machine, Outlook (and again, particularly Outlook Express) is going to be a source of trouble.
Aside from anything else that might happen, large mailbox folders are apt to break. You may get locked out entirely or you may just be unable to delete messages or receive new emails. Sometimes you can fix this (there are Outlook mailbox repair tools - scanpst.exe is Microsoft's but there are others) and sometimes you can't (or at least can't fix the problem without losing mail).
Because of Outlook's bad design, I prefer to see people use IMAP or, for Kerio servers, the Kerio Outlook Connector. Either of these can allow local storage in addition to the normal policy of keeping emails on the mail server.
With Kerio, you do have another option: a very well done, browser agnostic, webmail server. The only disadvantage is that you have no local storage unless you explicitly copy messages to local folders. It can be difficult to train users out of the habit of clicking Outlook for mail also, but otherwise Kerio's webmail does everything the mailserver can do and does it very well. It certainly eliminates almost all client side support issues.
Mail delivery problems
See Some common email problems for this type of problem. Many of these issues
come from user error or other factors that have nothing to do with using an in-house mailserver or something hosted. One issue that does (usually) only affect in-house servers is your IP ending up on a mail blacklist.
I have this Help - I'm on a blacklist article that suggests ways to deal with that. Note that many of the causes would actually have nothing to do with your server - it's just that having the server enabled you to know that you have the problem (compromised internal machines).
Another possible problem comes from Incorrect Reverse PTR records. As that article explains, you can bypass this problem by sending outgoing mail through your ISP or some other mail server that will allow you to relay.
All mail servers create logs. If you are running Sendmail or some other free mail server, you'll want to use "logrotate" to control the size of logs. Kerio has log rotation built in - see my Kerio Configuration article for advice on setting those policies.
Disk storage is so cheap today that this is not the problem it used to be, but of course it still can happen. Backups and archiving can consume large amounts of storage; retention policies should be reviewed regularly.
Users create their own storage problems, particularly those who refuse to delete any email. As annoying as that may be to the administrator, we do have to admit that having access to old messages can be important.
Upgrades can be scary. No matter how good the beta program, sometimes things slip through and you are the unhappy customer that has just the right conditions to find the bug that nobody else noticed. Lucky you.
Consider this, though: if you are with a hosted service, you have no control over when they choose to upgrade and you have exactly the same chance of being the unlucky person who trips over the problem. If you were controlling this yourself, you could immediately down-grade if the problem was really that serious. Convincing a hosted service that you need them to revert because you have an obscure issue that none of their other customers have might not be possible. Wouldn't you rather have control?
Really, that's the main reason to host your own server: control. Oh, sure, internal email gets delivered quicker, you don't have to worry as much about the security for internal emails, but the main benefit is control. Control of users, control of aliases, groups, quotas... that's the real payoff.
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