The below image came from here.

Update: Looks like the above image is fake. Here is the real one: (https://adwords.google.com/select/images/gmail_screen.gif)

Update: Apple's G5 XServe To Power Google's New GMail
Update: Click Continue reading for full sized screenshots of Gmail
kinda looks like Y!Mail to me...
Posted by: Massimo Moruzzi | Apr 05, 2004 at 01:41 AM
That fake screenshot is Yahoo mail, but the others look different. Duncan, I don't think you gave credit for the last two shots.
Posted by: Elliot Lee | Apr 05, 2004 at 04:42 PM
You are right I didn't credit them. I don't know where they came from because they were emailed t me... Any idea where they came from? You tell me where these shots came from and i'll give credit where credit is due... I think the first screenshot is actually a SquirrelMail theme not yahoo mail...
Posted by: Duncan | Apr 05, 2004 at 05:08 PM
Dunno, they appear to be from fury.com (also shown in the screenshot).
Posted by: Elliot Lee | Apr 05, 2004 at 05:26 PM