I discovered this trick after much googling but it worked instantly for me after applying it.
1. Log onto your wireless router and find the page that lists the IP addresses for all of the computers on your local network.
2. Look for the name of your iPhone and write that IP down or paste it into your text editor of choice.
3. Fire up Terminal.app or Putty.
4. Type ssh root@
5. You should now be prompted for the password for our iPhones root account, by default this is alpine.
6. Next, you should be prompted by your computer if you wish to accept the RSA key for the server your connecting to, type yes.
7. Type in cd /var/mobile/Library/
8. Type in chmod 777 Mail
9. Try launching Mail on your iPhone
If this works you should now sync your phone so that the permissions carry over to your backup. This trick worked for me but I don't know if it works for everyone. I discovered this trick here. Please let me know if you have any issues with this, next up on my list of things to do isto figure out why Yahoo won;t connect on my iPhone. . .

Guy Lewin
Gatewayy, you are so lucky to even have an iPhone...
It didn't arrive to Israel yet, but when it will, I will try buying it because it sounds awesome.
2008-03-07 10:16:29