How to Send Files with MacBook Messages
Need to send a file to a buddy? It’s simple! To send a file to a buddy through MacBook instant messaging, click the desired entry in the buddy list and then choose Buddies→Send File. Alternatively, you can
Use the cmd+Option+F keyboard shortcut.
Right-click the buddy in the list and choose Send a File.
Drag the file from a Finder window to the person’s entry in the buddy list.
Drag the file into the text-typing window.
How’s that for convenience? No matter how you start the transfer, a dialog appears to indicate that the recipient is being offered a file transfer request. If the file transfer request is accepted by your buddy, the transfer begins and is saved where the recipient specifies on his or her system.
If a buddy sends you a file, the Incoming File Request pane appears. You can then either click the Decline button (to decline the file transfer) or the Save File button (to save the incoming file to any spot on your system).
To send a file during an iMessage conversation, choose Buddies→Send File, use the cmd+Option+F keyboard shortcut, or drag the file from a Finder window and drop it into the text box in the Messages window.
Always check any files that you receive from Messages with your antivirus-scanning software before you run them!
If you’re looking for another easy method of sending files between Mac computers running Mountain Lion, don’t forget to check out AirDrop. Messages does, however, have two important advantages over AirDrop: The two computers don’t have to be within Wi-Fi range of each other, and Messages can transfer files with a wider range of computers (PCs running Windows, Macs running older versions of OS X, and PCs running Linux)