gmail_to_fastmail.md

Proceed at your own risk. Back up. Don't blame anyone but yourself if you lose all your email or send your personal information to a nefarious third party.

Source: http://hynek.me/articles/fleeing-from-gmail/

1. On a VPS to increase speed (I used a Digital Ocean VPS):

    wget http://imaputils.googlecode.com/svn-history/r5/trunk/imapcopy.pl
   

2. Create a text file called map with the following contents:

    [Gmail]/Sent Mail:Sent Items
    [Gmail]/All Mail:Archive
   

3. Using screen, open up some stunnels. In two separate windows (so both continue to run):

    stunnel -c -f -d 1143 -r imap.gmail.com:993 -P ''
    stunnel -c -f -d 1144 -r fastmail.fm:993 -P ''
   

Note that you may need to replace fastmail.fm with mail.messagingengine.com.

4. In yet another screen window run the following, replacing the user-specific stuff as necessary (including an app-specific password if you're using 2-factor authentication for Google):

    perl imapcopy.pl \
      -S localhost:1143/your.google.name@gmail.com/google.password \
      -D localhost:1144/your@new.account/new.password \
      -M map -m "[Gmail]/All Mail,[Gmail]/Sent Mail"
   

5. Wait. This may take several hours (I left it running all night for 55,000+ messages). When you're done, change your Google and FastMail passwords for security purposes (or delete your app-specific Google password).

I found that on my UK Gmail account, the folder prefix [Gmail] didn't work.

Number of mailboxes to process: 2
unexpected response: 1 NO [NONEXISTENT] Unknown Mailbox: [Gmail]/All Mail (Failure)
   [Gmail]/All Mail mailbox is empty
unexpected response: 1 NO [NONEXISTENT] Unknown Mailbox: [Gmail]/Sent Mail (Failure)
   [Gmail]/Sent Mail mailbox is empty

Instead, I had to change this to [Google Mail]

perl imapcopy.pl \
        -S localhost:1143/your.google.name@gmail.com/google.password \
        -D localhost:1144/your@new.account/new.password \
        -M map -m "[Google Mail]/All Mail,[Google Mail]/Sent Mail"

I had to use stunnel3 on Debian unstable (the stunnel4 package contains both and defaults to 4, which couldn't parse the options) to get it to work, and use the [Google Mail] prefix, too (German account).

http://imaputils.googlecode.com/svn-history/r5/trunk/imapcopy.pl doesn't seem to be available anymore