Gmail – How to Compose an Email Without Seeing Inbox

If you can import the EML files into a mail client that support IMAP this will be easy.

It seems that Thunderbird can do this, but I'm not 100% sure. (Don't have a local copy to play with.)

Anyway, set-up Thunderbird to be an IMAP client for Gmail. (Lifehacker has an excellent guide to do this.)

Then, import your EML files into Thunderbird.

If necessary, move them to a temporary folder (called "Zimbra" perhaps) which will be a label in Gmail. Then just wait for IMAP to sync them all to the cloud.

After that you can delete Thunderbird, keep it around to make local archives of your e-mail, or keep using it as your main client.

I was able to do this a couple of years ago with thousands of messages from my Pegasus Mail client. (There was some pain in converting to a format that Thunderbird could read, but getting the messages into Gmail was the easy part.)

This works great. Someone wrote a script in a Google Doc which can send an email in HTML. Just copy/paste the HTML in the script's dialog box and set the to, cc, and bcc and it'll send it using your google account with which you are currently logged in.