Most lawyers communicate primarily through email. At the same time, lawyers need to take reasonable efforts to prevent disclosure of client communications and information. Are these two things in conflict? Potentially.
It's fair to say that email isn't the world's most secure communication system. For one, the NSA regularly intercepts attorney-client emails, by its own admission. Then there's the risks posed by hackers, by snooping email tracking software, by your firm's noisy IT intern. Don't worry though -- you needn't abandon email and strap on a tin foil hat. Not yet at least. There's still several easy ways to make your attorney-client emails more secure.