For the last five years I've run a virtual server from the excellent Linode which has hosted a number of services including this web site, a Jabber server, some other web sites, and my email. Initially I did spam filtering myself, but between the load this placed on the server and the constant tweaking required, it annoyed the hell out of me, so I outsourced that to JunkEmailFilter.com, which while imperfect was passable.
I've used mutt as my email client since some time in the later 90s, after upgrading from pine. The advantages of a text-mode mail client were speed, accessibility from nearly anywhere, integrated tools (gpg, lbbdb) and the fact that a clueless boss looking over your shoulder will think "techie stuff, must be work" and hence not require me to justify my work throughput.
More recently I've noticed myself regularly bouncing messages to my secret gmail account. Partly this is because Google Reader produces broken text attachments, and a few of my correspondents insist on using that, but mainly it's because more and more emails included stuff I couldn't use in a text-mode client, like links to complicated web site, pictures, or links to videos.
So I thought I'd try out moving all my email to Google excellent web client. The process of moving the whole domain was surprisingly easy. Just point the MX at Google's servers, set up the appropriate accounts and define the pass-through mail server for anything that doesn't have an account on the Google servers. This means the mailing lists and weird aliases I have on my server continue working as before.
The hardest part was uploading all my old mail. I've been saving mails into their own Maildirs based on the big before the @ in the email address, so email@example.com ends up saved as john/ and if there's any doubling up of "john" it's still all in there. Gmail has a pretty good (and very fast) search, so filing becomes much less important.
There's a bunch of tools you can find that claim to be able to upload Maildirs to Gmail. I couldn't get any of them to reliably work. Eventually I downloaded the corpus of my Maildirs to a desktop and used Thunderbird to upload them all to the new location. It took ages, but it worked.
So far I'm pretty damn happy with this. I haven't had a single spam get through, and even the ones that make it to the Spam directory are pretty minimal. The add-on Postini spam filtering service has done two false positives on spam so far, which I consider pretty good and I presume it'll learn.
Now that I'm paying US$50/year for each email account (one for me, one for Holly) it's costing about the same as my former JunkEmailFilter.com and rsync.net accounts. I'm also going to downsize my Linode which will also save me some money. More importantly, I'm doing even less maintenance, and the search engine on my email is vastly superior to mutt. It's also a graphical email client, which is nice, and the mobile clients are really quite good.
Quite happy with it.