The GMail application for s60 seems to be crippled. Actually, the m.gmail.com website is affected too. How, you ask? Well, have you tried downloading a zip file to your mobile from the GMail application? No? Well, if you do, all you get is a plain text listing of the zip file contents. There does not appear to be any way to download the actual zip file. Worse, if you own a phone with a decent web browser and go to m.gmail.com and try - all you get is a notification "1 attachment." Lovely.
The solution was to turn on IMAP and then setup IMAP in the Nokia Messaging application. This finally allowed me to download the stinking zip file. Hurrah. I'm just glad I have a phone that has this feature.
The attachment I was trying to download was the highly sweet game Lament Island. I bought it on a friend's PC and didn't want to install the Nokia phone manager software (not to mention that I didn't have my data cable.) This isn't all that unusual. What if I had a colleague send me a PowerPoint for a presentation I was giving? I would be totally SOL, if it wasn't for IMAP.