This is not legal advise and with all things consult a legal expert. I know many lawyers are worried about the ABA Model Rule of Professional Conduct 7.3 which is unique to lawyers and basically prevents lawyers from cold calling for "pecuniary gain". They forget that the law only prohibits calls to solicit for “pecuniary gain" but there is nothing wrong with offering something for free with no intent for pecuniary gain.
For example, when Datetree Digital calls on behalf of B2B lawyers, we say something like: “I'm calling on behalf of [Legal firm branding] about a monthly seminar we’re offering to companies about how to avoid traps and pitfalls with legal contracts. Do you deal with contracts?………(depending on the lawyers specialty and by the way you don't have to give this seminar live. Just use a software program that gives interactive, close to live seminars on your behalf that you record once, with live chat questions being answered for you).
The seminar is given and at the end of it simply say here is our website, and here is a link to set an appointment to have a deeper conversation about any topic you want to build a relationship now before you find yourself in a painful situation where you really need legal services.
This method is a direct way to get vetted, qualified leads with out breaking any rules. There are other strategies of course, but the point is a lawyer can have cold calling done for them.
There are many misconceptions about cold calling among professional services in many B2B industries and I encourage professionals to just set an appointment and speak with an expert instead of making assumptions.