Dear....,
We value your work with us as an employee, and we hope we can continue procuring your services on mutually-beneficial terms. As we discussed on [DATE, ex. ....], the company greatly values ...... Since I personally know you to be a conscientious, courteous and friendly individual, it came as a surprise to me to hear [NATURE/CIRCUMSTANCE OF BAD BEHAVIOR, ex. of the incident yesterday;................]
I understand that the nature of work these days is often frustrating. However, as you know, we simply can’t afford [RESULT OF BAD BEHAVIOR, ex. to have dissatisfied customers]. Nonetheless, [NAME, ex...], I am confident that this is merely an extraordinary circumstance, which is not in accord with your friendly character. I cite your past history of exceptional performance as proof.
Please contact me if there is something I can do for you.\