Congratulations on Promotion
Allow me to take this opportunity to personally congratulate you on your promotion. It is a pleasure to see that you have been recognized you for all your hard work and talents. That, along with your loyalty and commitment to __(name of organization)__, makes you most deserving of this promotion.
Without a doubt, __(we have all/name of organization has/many have/etc.)__ benefited from your tireless efforts. Though you will be duly missed in the __(name of department/branch/etc.)__, it is great to see you in the new position of __(type of position)__. __(I/We all/etc.)__ know that you will also do exceedingly well in this position. Once again, congratulations on your promotion, __(Name)__. It looks good on you and I wish you the best of luck and greatest of success in your new role.