28th March, 2008.
Dear Ms. White,
I am writing to bid you farewell, as I leave ABC Company on 1st April and move on to San Jose to take up another appointment. As you know, the move has been prompted because of family requirements.
I would like to take this opportunity and thank you for all the guidance and support you have given me during my tenure here. I have grown not only professionally but personally as well because of your invaluable help and advice.
I look forward to keeping in touch with you. My email id remains the same and I shall send you my new contact details at the earliest.
Thank you for everything,