if your lawyer uses google, microsoft or apple for email, maybe better look for another lawyer...
everything one of these (or other) giants know can be assumend to be compromised already in one way or possibly many others or at least in near future.
imagine you email your client some note, that he should carry some documents next time and the giant running word probability algorythms only to look later at the real outcome of the trial and the tactics used by you in front of court to be able to warn THEIR customers about what YOU might currently try to do in front of a court to win against someone. it intentionally removes parts of the value of your work to sell that to their customers while using data that is supposed to be private for reasons.
a lawyer who gives away hints about any of his actions to a tech giant NOW has a high probability that his work isnt worth a dime any longer in mid-term future only because of how lazy he was with his and his clients privacy TODAY.
just to mention.
the point is that people who don't care go to lawyers to tell them how to move forward with appropriate caution. and privacy with a lawyers actual communication should be included. remember how lawyers (in movies tbh) often say 'let me talk, dont say anything at all', thats "maybe" because saying anything could reveal something the other party could use to win. if that doesnt include emails to be private, then why not directly use facebook or 4chan instead to tell the ither party how to win against your client? *lol
so if your lawyer doesnt take specific caution into account by himself what he would be supposed to tell you to do anyway, that lawyer is imo at best a risky bet.