A friend, (TWITTER) @rguareschi asked today:

“How can I export my thousands of emails from Gmail to other providers? #neutrality”

So this question inspired us to explain the easiest way we found. You have to use imapsync

http://freshmeat.net/projects/imapsync/

The way to do it in Linux, with SSL Auth:

BE CAREFULL: All the dash signs are actually double dash: –host1 is – - host1 (without spaces)

This will sync all the folders from one host to another.

imapsync –buffersize 8192000 –nosyncacls –subscribe –syncinternaldates \
–host1 FROMHOST –user1 YOURUSERNAME –password1 YOURPASSWORD –ssl1 –port1 993 –authmech1 PLAIN \
–host2 TOHOST –user2 YOURUSERNAME –password2 YOURPASSWORD –ssl2 –port2 993 –authmech2 PLAIN

You can play with this options. For example, if you only need to move one folder, use:

–folder FOLDERNAME

Example:

imapsync –buffersize 8192000 –nosyncacls –subscribe –syncinternaldates \
–host1 mail.google.com –user1 zenware –password1 nomyrealpass –ssl1 –port1 993 –authmech1 PLAIN \
–host2 mail.zenware.net –user2 mauricio.romano –password2 sogoodsofar –ssl2 –port2 993 –authmech2 PLAIN –folder Sent

And so on.

Hope this helps.