We all need lawyers at some point in our life. People in certain professions need to be addressed in a standard salutation form.
I came across this very useful site, which you might like to use as reference point for various professions. Here is the link as to how to address lawyers and attorneys: http://www.formsofaddress.info/attorney.html
What other useful information you might like to share from your own experiences with lawyers and attorneys? Any useful tips you might like to share with our audience?