How can I E-mail multiple photos ? How do I e-mail multiple Photos from MAC desktop with Yosemite? What is keyboard shortcut to select multiple images and e-mail them?
You can use 2 methods.

One is to hold the "shift" key that will select a continuous group from first to last click.

The other method is to selectively select them.

Click on the first one than HOLD the cmd key and click on next one and so on while holding the cmd key.



When done selecting release the cmd key, right click on the selection and use the share- email.

Be aware that emailing to large files might fail.

In email check the size and decide if to make it smaller.



Mail will tell you when to large so either select less or use the "Image size".