When my version of PS Pro ceased working due to a MS Windows 'upgrade' I searched around for a means to compress jpg files and found this
JPG compressor
I have the free version and it is really simple to use; open a file and the left hand window shows the original and the right hand a compressed version which you can save with a different name if need be. The example below has has been compressed from 1473kb to 264kb

There is nothing worse than an in-box frozen by large image files and this software will let the sender avoid causing this.
(The image is my current Tide Class project compared with the older Mountford version)