From compose window, click View>Toolbars>Composition toolbar. I think that will do it.

I followed your instructions, but the toolbars are all clicked on and I cannot see how to do anything else.

Okay, go to compose window, click view>toolbars. I assume 'compose tool bar is checked. Now, click customize and drag 'send' up to toolbar. Please confirm that this worked. I just tested myself. I removed from toolbar and added back.

I am sorry but I do not know what "Compose" window it; if I go to view on the main toolbar, and I click on "Customise", I find lots of instructions but no "Send".

I'm referring to the window you view when you click 'write'. Once you are at the point of writing (composing) a message, click view>toolbars. If the compose toolbar is not checked, click it. That should cause SEND to appear. If it is not checked, then follow original instructions above. Let me know.

Sorry, I thought you meant the "write" window, but this one does not show me any toolbars with the word "view". It has only got the "from" "to" "cc" and "bcc" and then the next line is "topic" but no toolbars at all.

Okay. I know exactly where you are now. Again, go to the 'write' window. Click F10 which brings up a tool bar at top momentarily. While it is there, click View and then tick on the Menu bar and the composition bar. That should do it for you. Let me know.