Ok, so I've been struggling to figure this out for a couple of days, and while it wouldn't appear to be rocket science, a solution is surprisingly elusive.

So, here's what I'm trying to do. Due to gmail's arbitrary data storage limits, I want to download and backup all my gmail emails on my local machine. The "easiest" way I know of is to use a mail client, so Thunderbird it is. I use getmail on my linux machine but I would prefer to have a copy on my Windows machine since it's used far more often and quite frankly faster to access mails when I need them.

I have set up my Gmail account to use IMAP, with the option to leave messages on server (instead of deleting) selected. Gmail has downloaded all messages (not just headers) due to this configuration:

• mail.server.default.mime_parts_on_demand = false

• mail.check_all_imap_folders_for_new = true

• mail.imap.use_status_for_biff = false

So, I have all the emails downloaded and stored within my @gmail.com account within Thunderbird.

Enter the problems:

1. What I want to do is save these emails locally, but I can't get Thunderbird to move/copy the emails from my @gmail.com account in Thunderbird to my Local Folders. I could manually copy them but I would prefer it be done automatically because constantly selecting emails and manually moving them isn't exactly how backups work.

2. This is the far more obnoxious issue. Right now, the email downloading/synchronization is working fine, but the goal of this backup mission is so I can delete emails in gmail that were received eons ago but keep them stored locally because they may still have valuable attachments or other content. By deleting them on GMAIL WEBCLIENT only, I should be able to get rid of the obnoxious usage messages without actually losing the emails since I'd be storing them locally.

But the problem is, when I delete a message within GMAIL WEBCLIENT, IMAP decides to be brilliant and then automatically delete it from my local Thunderbird gmail account as well. This entirely defeats the backup purpose, as the point was to keep all my old emails locally and be able to delete them on the gmail server. If I delete them on gmail and they get removed locally, then they aren't really backed up.

I assume there is some setting that I'm missing or an extension I need or a way to automatically copy from my local Thunderbird gmail account to a local folder that never has mails removed for any reason, but for the life of me I can't figure it out.

Any ideas?

Edit: Obligatory sysinfo

• Thunderbird 17.0 (latest release).
• Windows 7 x64
• Personal gmail, non-custom domain.