MacOSX Mail.App to GMail
I've been moving to GMail lately. The original reason was being out of the office fairly often these days, and a good webmail is very convenient. And GMail's search-based features rock!
My mail archives are stored in my macosx's Mail.App, and in recent versions Apple has moved away from the mbox format for storage, so the move is a bit more involved that I'd have liked it to be.
Here's my recipe:
Start with the cosmicsoft emlx to mbox converter. I'd have preferred a command-line thing, tried Jamie Zawinski's emlx converter but the output format didn't seem to be correct.
Next, add a marker in the subject lines, and setup a filter in GMail so that messages are marked with the correct GMail label. You don't want thousands of old messages in your inbox.
sed s"/^Subject: /Subject: (whatevername-g) /" mbox-with-markers
Finally, use Mark Lyon's GMail Loader to forward the contents of the mbox to your GMail account.
It takes a while...but it'll be useful to have everything there.
Is it safe? I trust Google more than myself about backups, for sure. And there's no privacy in unencrypted email anyway, so I don't care much about what they do with the data.