I set up my email on the iPhone with gmail (using the Gmail icon from Mail) and it downloaded the last 50 emails.

Now when I go to check email the progress icon spins and it says "Checking for Mail" but then it doesn't download any mail. If I log in to the web interface I can see my new mail.

Is it just me or is this happening to other Gmail users?

Edit: Just turned WiFi off and it downloaded my mail fine using 3G.

Thing is I can browse fine using WiFi, just the Mail app doesn't work. It does that with my WiFi at home and at work. Does the mail app initiate an incoming connection that my NAT router doesn't have firewall rules for?

I've experienced issues with accessing gmail to my nokia since the iphone release. Some threads would indicate the networks are overloaded with the iphone. Lots of gateway timeouts with the S60 gmail app, but no issues with loading gmail login page via opera browser.

Weird.

i've had some funny Wifi problems too, same sort of senario.

gmail + 3G = download & read mail, all is good.
gmail + wifi = forever loading.

i've found that if you maunally reload it it seems to work. my router is set up for any incoming connections (no neighbours to steal my 'net) so it doesn't appear to be a wifi problem, unless i've completely missed something.

and i probably have.

vietnow, yes, that's pretty much what I'm getting. Mail + 3G works, Mail + WiFi doesn't work.

On the phone to Apple support. They're not terribly useful. Edit: On to second level support now. Usefulness is increasing. Still no answer why, apparently it's "wierd".

Edit: Got a call back. I'm going to set up my Outlook client to download mail using IMAP and see if that works or not.

Not sure if I read this solution on mactalk or elsewhere, but switching between 3g and wifi you need to turn off and on the iPhone or it doesn't download mail. I'm not using gmail so I don't know if this is the same problem, but this works for several of my pop accounts with different servers.

Well I think the imap.gmail.com server was down. I couldn't connect to it from a PC on the LAN earlier today and mail wasn't working on the phone. Now I can connect to it from a PC and guess what, mail on the phone is now working.

I think it's a problem with the gmail infrastructure, not an iPhone issue.

i can confirm that regardless of wi-fi/2g/3g that mail downloads fine for me, without the need to restart or whatever. (occasionally mobile me's pushes dont get through but i think thats teething problems)
using .mac imap and zimbra hosted imap/exchange.

its not a pop/imap thing?

Same here, no issues accessing gmail using mail on wifi/2g/3g. I don't like the way Gmail handles its IMAP (when I tried setting it up with mail on a MBP), so stuck with POP on the iPhone, no problems.