How To Write A Job Offer Acceptance Letter? I am writing to confirm my acceptance of your employment offer on April 20 and to tell you how delighted I am to be joining XYZ Corporation in Chicago.I have accepted a offer letter and signed on it, but my joining date is 2 days away. Learn how to write a professional job offer letter acceptance mail reply with joining date with an easy format and practical samples. A job acceptance letter lets you outline the details of the job so that you are clear about your role in the company prior to your joining. Join Pretzel Rewards today and treat yourself to 5 free pretzels, on us!