Check and see if your views are correct. When you have a
new message open, click view, then toolbars and make sure
there is a check mark next to the word standard. That
should bring up the toolbar with the send button
hold your pointer on it, it should say "more buttons."
Click on this and you should find your "send/receive"
icon. Click on it and it will show up on your toolbar.
(If you don't use this button often, it will hide until
you use it again.)