Icons disappeared at bottom of list of mail!?

Those icons only appear if you have an individual mail selected. If you are just looking at the inbox, all you will see is the refresh icon and the create icon along with the date/time the box was updated. Once you select an individual email, you should see 5 icons, the two I listed earlier plus the folder, trash, and reply icons.

If you are looking at an email and still do not see them, you may need to either power the phone off/on, or do a reset, holding the home and power button together until you see the Apple logo and then release, ignoring the slide to power off screen.

Your welcome. Glad I could help. Most minor issues and many of what people seem to think are major issues can generally be overcome by just a reset of the phone. Many require a little more, such as a restore, but like you said, it is like a mini-computer and needs a litle "jump start" every once in a while.

I did a reset of the home screen layout and my reply/forward icons are still missing! They were there yesterday!

Not a reset of the home screen layout, a reset of the phone. That is accomplished by holding down the power and home buttons together until you see the Apple logo and then releasing, ignoring the slide to power off screen. That is the second step in user troubleshooting. See if that helps. All it does is reboot the phone, you will not lose any data.