Dear Hiring Manager,
I came across the Virtual Assistant position you recently advertised and am very much interested in offering my services. My experience as an office staff for several years is a great match for your needs. I offer you my strong computer experience, skills, and office assistant abilities.
In addition, I am also trustworthy and can handle sensitive and confidential matters with discretion. I'm certain that I will be able to offer an immediate contribution to your organization if given the opportunity.