The newest release of GMAIL for Mobiles 1.50.1193, one of the features claims that it will automatically refresh your inbox. After searching high and low on the gmail application for my E65, I couldn't find such a feature. Then I checked Google mail's help center and found this:
Does the Gmail for mobile application support auto-refresh?
So technically, it doesn't support auto refresh as you may be imagining. Anyway, no harm done because you are only saving seconds by having to press refresh manually and gmail for mobile doesn't alert you when you have new mail anyway.