An Interesting Kerio Problem

I went to see a Kerio customer this morning. This isn't my direct customer; the installation was actually done by their ordinary computer support folks, and I normally deal with them. However, the customer has been complaining about performance and spam, so I went on-site to check on it.

I found that they were using Outlook and Outlook Express clients, all set to POP. That's not what I had recommended - for one thing, it means users have no access to the Junk Mail folder where Kerio puts Spam and it also means that Kerio can't learn about spam - if they were running Imap, dragging a message to Junk Mail helps train the spam engine. So not only can't the server learn about Spam, but they need to set the Spam threshold higher than normal to avoid false positives that they have no convenient way to retrieve.

But that wasn't the worst of it. Each users account was set up to leave a copy of each message on the server. That's good - it means that if you access from outside by Webmail or an iPhone or other device, you'll see a consistent view of your folders. However, they had not checked either of the deletion options (delete from server after so many days or delete after the message is locally purged). That means that every single message ever received is still on the server!

That will definitely impact performance. It's fairly easy to fix - see Fixing Large Kerio Mailboxes - so I have sent their support folks full instructions for doing that. I've also suggested that they at least consider using Imap or Webmail to get better control of spam