Hello Fgtunv,
I am Rex and I am writing this letter to apply for the position of Back office Office Assistant in your company. I saw the job posting on the website and I am very interested in this position.
I have experience working in customer service and I have excellent communication skills. I am also proficient in Microsoft Office. I am a fast learner and I am confident that I can do the job well.
I am excited to work in your company and I am confident that I can be a valuable asset to your team. I am looking forward to hearing from you.
Thank you,
Rex