Good day [recipient],
Please be informed that we have assigned a new representative to preside over your area. [Full name of representative] is very well versed in the production of [product]. We hope that you can benefit from having his expertise in your area while you work.
Please expect [name of representative] to arrive in [area] on [date]. If you have prior engagements on that day, please coordinate with us to set a more appropriate time.
[Name of sender]