Backing up mails from gmail server

This may be one of the most answered question. However, I could not find a satisfactory answer on Internet.

Requirements:

1. Download all gmail data on a local machine

2. All downloaded mails should have the same labels as on the server

3. Delete all mails on gmail server. This change should not be reflected on local machine.

4. Pack local data and store it somewhere and I should be able to开发者_如何学Python use it from other machine.

5. If I change my email client version, compatibility should be maintained.

6. I should be able to search it locally and I should be able to update the emails later.

Does anyone know a better way of backing up gmail data which can meet above requirements.

archivemail comes to mind. It retrieves and backups all mails from an IMAP account into a mbox file.

You may want to try:

http://www.codingsheeps.com/gmailarchiver/