Sending email from Finder

Yes, OS X does have that function, via "Services". with the item selected in the "Finder", go to "Finder" > "Services" > "Mail" > "Send File".

Edit: If that's too much of a hassle, you can assign a keyboard shortcut to it using the "Keyboard & Mouse" pref pane.

alternatively, you could also use Automator to create a Finder plugin accessible via contextual menus/right click. The advantage to this method is the ability to create a plugin with a preset recipient, subject, user mail account etc...

- Launch Automator
-Choose 'Custom'
- /Library/Files & Folders, drag 'Get Selected Finder Items' to the right
- /Library/Mail, drag 'New Mail Message' to the right and below the first action.

Under the File menu, 'Save as Plug-in...' and use Plug-in for Finder from the pop up. You can also choose to save it as a plug-in for the Script Menu (main menu bar) if you've enabled that.

Note: with the "New Mail Message' part of Automator, you can specify a great deal of information for the plug-in and subsequent new mail message which will save you having to type as much.

of course, it's just as easy to drag the document to the Mail icon in the Dock (assuming you've left it there). It will open mail and attach the file within a new mail message.