If your colleague does not have Photoshop software or related products installed, (and since Safari will not open a psd file), the simplest solution is for you to change the file format to jpg or tiff before sending to the colleague. Another option is for him/her to Google "psd to jpg converter", but it may not be worth the effort.
Do they get any error message or what exactly happens when they try to open it?
Solved : luckily it has been enough restart the mac. Thanks for the answers and your time