Originally Posted by 2012
On the phone it seems to initially just collect the email title and who its from. Doesn't download the actual message to your phone. If you want to read an email which is listed on your phone but at the time you have no network connection it just says loading.... and the message isn't there to read.
That's to save battery, data usage and space on phones with limited storage. It's not the same thing as webmail like Yahoo mail, Hotmail etc.