We use an app called fotosizer, which is pre-installed on everyones workstation.

You simply drag and drop the photos, or the folder containing the photos, into it and click Start.  Do not change the settings as they are preset for 2048x1536.

It will replace the original files, so be aware of this.

**Do NOT ever resize photos attached to an insurance claim or investigation.  For legal reasons they must stay intact and cannot be modified.