同事離職時，可以送上以下英文祝福語：
Try not to become a man of success but rather to become a man of value. 祝您成為有價值的人，而不是僅僅追求成功。
I will cherish the memory of working with you and wish you all the best. 我將珍惜與您共事的回憶，祝您一切順利。
Enjoy your new job and life. 祝您享受新的工作和生活。
Congratulations on your new job - good for you! 恭喜您獲得新工作，祝您一切順利。
We will miss you and have fond memories of working with you, but wish you well and hope you attain all the success you deserve. 我們會想念您，但希望您在新崗位上取得成功。
Your loyalty and work ethic have been an inspiration to us all. 您的忠誠和職業道德對我們所有人都有啟發。
以上祝福語均表達了對同事離職的美好祝願，希望對您有所幫助。