Cannot get Mail of Iphone 3GS

I cannot get mail from gmail. Message states Imap.gmail.com not responding. I have tried re-typing the password but have not been able to get any mail for 8 days now. I am worried about deleting account and re-entering as I have three different email addresses coming into the one gmail account and originally had it set up for me by 02. Never had any problems in the 20 months I have had the iphone until now. Only wish that I had an Apple store in my area - Blackburn.