Just a note primarily for customers who have been using our email service, with Dspam. We think we have the issues of recent weeks resolved.
After years of our mail server chugging along happily delivering mail, the past year has proven to be a bit more challenging. The bottom line is that with the proliferation of free email hosting and services like Google for Business, email hosting is a commodity nobody is willing to pay for, at least not for the kind of service we think is worth doing.
The thing is, we'd much rather be building great web sites than trying to talk a customer through getting their newest tech gadget to download email from our servers. So we've basically quit doing that, aside from a handful of clients who've hosted with us for years.
However, I personally don't want Google to know everything about me -- they know too much about me already, I'd like to at least maintain some illusion of privacy by at least keeping my inbox off of their servers. Ads that take context from email are creepy, and so I'm willing to put up with the pain (and cost) of running our own mail server for that reason.
The challenge is spam. SpamAssassin blocks a huge amount of spam on our server, but even after that's done half of what's left in my mailbox is still spam. So we've been using a very cool statistical analysis tool called Dspam to catch the rest. And it's been working great for a long time, aside from a hiccup last year when we had to dump the training database due to disk issues.
In the past month, however, something has taxed the server to the point where Dspam was starting to back up messages, as much as 3 hours. This started happening every weekday morning, for hours. For the past couple weeks I've been shutting off Dspam and letting the mail deliver, just so we could get at messages we were expecting -- but flooding our mailboxes with the spam Dspam normally catches.
The fix? Change the database storage engine. We switched the token storage table from MySQL's "MyISAM" table type to InnoDB. This took over a day to complete, with the spam filter off. But it seems to be working beautifully -- the longest delay I've seen since making the switch is 3 minutes, far better than 3 hours!
And I think this switch has fixed one other nagging issue -- ghost bounces. I've had several reports of messages to me bouncing, but I've actually received the messages in question -- I think what's been happening is the database has been timing out on large messages, so Dspam has thrown an error and delivered the message anyway. With a faster database engine that locks at the row level instead of the entire table, this isn't happening anymore.
So there's probably way more about mail servers than you want to know...
What I want to know is whether you care enough about the privacy implications of Google or Microsoft or Yahoo having your inbox and all your email to pay upwards of $100/month for hosting a few mailboxes? With a few customers who cared at that level, we could actually support updating and maintaining a mail server we want to use anyway.
SpamAssassin is probably the trusted anti spam software on the market today.