Email setup on iphone on o2?

Hi,





I can get my email on the iphone, but I can't send any.





I am guessing that I need to use a different smtp server on there from my computer. If I do, what is it?





Thanks

Email setup on iphone on o2?
I have an Iphone you can send mail out by just pressing reply. I have had the old Iphone and now i have the new one you can press compose mail when you go into the mail icon or you can press reply on the top the reply to someones email