Both are acceptable. Esq. is simply an abbreviation of the word esquire.
The traditional title for a lawyer is "Esquire", which is abbreviated "Esq.". Therefore, on the invitation you would write John A Smith, Esq. if his highest degree is JD. If he has also received a PhD, you could write Dr. John A Smith, Esq.
It depends on how pompous the attorney is. Some lawyers love to throw their titles around. For these people, write: John Smith, J.D. (juris doctor) or John Smith (esquire) or John Smith, Attorney at Law Most lawyers though, don't care how you address them as long as it is respectful. Just write: Mr. John Smith or John Smith.
Esquire is a (now old fashion/'proper' as my Mum would say) of addressing a gentleman on the envelope. You don't use any title so it is David Smith Esq. rather than Mr. David Smith, the letter would then use the salutation 'Dear Mr Smith'. Should only be used with full names, ie D. Smith Esq is NOT correct. If the person has another title (Dr/Sir) etc again use that and drop the Esq.
When addressing a letter to an attorney, it is more appropriate to use "Mr. Smith, Esq." The abbreviation "Esq." signifies that the individual is an attorney.
It is a now rather old-fashioned polite mode of address in letters and on envelopes. "mr. B. Smith, esq." was until some forty years ago common if you suspected (or pretended to suspect) the adressee to be well-born .
John Brown, Esq
Paul Benfield has written: 'Heads of objections to be enquired into before it will be adviseable to take Paul Benfield, Esq. again into the Company's service. Delivered to the general court of the East India Company, by Edmund Burke, Esquire. = Mr. Benfield's answers'
William van Mr Van esq.
Fox Sports never tendered a contract to Mr. Smith, as he acted as an independent adjunct columnist. Therefore, Fox did NOT fire Mr. S. A. Smith, he was politely asked to walk away to avoid legal action from our departmental attorneys and numerous cases pending before him, from external sources. Desmond Baxter, Esq.
Mr. Brian Jones, esq.
Mr. & Mrs. Smith
You would address an attorney as: John Q. Public, Esquire You don't put a Mr. in front of the name.