Introduce yourself, express enthusiasm about working on the account and set up a first meeting to get acquainted.
1234, Main Street
Boston, MA 02123
08 April, 2005
<Recipient Address Goes Here>
As you know, I have replaced <name of previous salesperson> as your account representative. I am working with <first name of previous salesperson> to come up to speed on all <his/her> accounts and am looking forward to working with you.
If you ever need to reach me, you can do so at <numbers to call>. I'll be calling you next week to set up a time to get together. In the meantime, please don't hesitate to call if there is anything I can do for you. I'll do everything I can to ensure a smooth transition. I look forward to meeting you.
encl: <List of enclosed items goes here>