The Google Email Uploader for Mac is a desktop utility for Mac OS X that uploads email archives from Apple Mail, Eudora, Thunderbird, and exported Entourage mail (along with other mbox and Maildir archives) to your Google Apps mailbox.
Google Email Uploader for Mac requires Mac OS X 10.5 through Mac OS X 10.7, and a Google Apps mail account.
Note: The application does not currently upload to gmail.com or googlemail.com mail accounts.
The application may be downloaded here.
Using the uploader
The uploader will try to find your mail archives in their usual locations on Mac OS X:
Apple Mail: ~/Library/Mail
Eudora: ~/Eudora Folder
You can add mail search locations or upload exported Entourage archives with the File menu.
Start small. Due to server upload rate limits, the uploader is fast for up to 500 messages, and slow thereafter (1 message per second.) Pick a small subset of your mailboxes when first trying out the uploader.
Be patient. Even after uploading completes, the server requires a while to process uploads.
Do assign a custom label (this is checked by default.) This lets you effectively "undo" the uploads later by deleting all messages with the label. Deleting the label itself will not delete the mail.
If you have many mailboxes in your archives, creating labels for each mailbox probably is not a good idea, as this could create far too many labels.
If the uploader does not accept your email address and password, check with your domain administrator to confirm that "User email uploads" are enabled on the administration page for Advanced Tools.
If your account has two-step verification enabled, use an application-specific password for the uploader.