As you know, I've been asked to take on the role of (job title). As a result, I will not be able to take care of the (name) account. I would like you to take full responsibility for this account, effective immediately.
I have full confidence in your ability to... Dear (recipient's name),
As you know, I've been asked to take on the role of (job title). As a result, I will not be able to take care of the (name) account. I would like you to take full responsibility for this account, effective immediately.
I have full confidence in your ability to provide innovative, creative ideas to the client and keep all projects on track. You are a seasoned professional and you will do well with this new responsibility.
Sincerely,
(your name)