I bought an 810 about two weeks ago, but I was about to return it as the default Email IMAP program simply doesn't work. I just found this:

http://modest.garage.maemo.org/

It worked great! Within two minutes, it was downloaded, installed, configured, and checking email.

I definitely have not tried everything. But hyperlinks in email messages worked and opened the web browser. Opening and closing messages was fast and easy.

It appears to access GMail folders fine. And GMail was already a configured service provider. All you had to do was select POP or IMAP (of course you need to have the matching setting on your GMail account).

I'm happy to be keeping this device now. My plan is to ditch my Treo and use the n810 in conjunction with an ultra-small phone. In order to do that, I needed email. Sweet!