For the most part, the individual reading your cover letter is a living breathing human being. (Yes, I know many companies use auto-reading software, but eventually your packets gets live eyeball time.) People like to be addressed by their name and title, not a generic To whom it concerns, or even the slightly less impersonal, Dear hiring manager. So take the time to research the actual name and title of the person responsible for deciding whether or not to interview you.
However, making a cover letter personal takes more than an appropriate salutation. The next step is to identify what the job entails and what kind of candidate they are looking for. It is perfectly fine to reference the job posting specifically in the cover letter. For example, if the job is for a paralegal with real estate knowledge say something like:
After studying both the your job posting and website I see that real estate expertise is vital to your firm. I have spent the past five years working in this field and would love the chance to describe to you in detail what I have accomplished, as well as get to know the exact area of real estate you most often deal with.
Finally, once you have properly addressed the individual reading your resume package and let them know you have made the time to research their company close by anticipating an interview. Confidently say that you are looking forward to meeting, state some questions you’d like to ask. Show the reader that you are prepared and willing to discuss all the various aspects related to the posted position.
A well written cover letter like the one described above will go a long way to landing you the interview, and ideally, the job.