Maybe, but maybe not, depending on the views of the court in questions. A good explanation is given by Michael Edward McCabe, Jr. in his article, "ATTORNEY-CLIENT PRIVILEGE AND WORK PRODUCT IMMUNITY IN PATENT LITIGATION." Here is an excerpt, with references and footnotes omitted (see the original for some important quoted material):
[C] Communications With Patent Agents
Apart from the issue of whether the substance of a particular communication qualifies as privileged is whether the persons involved in the communication can create a privilege. The attorney-client privilege applies to communications between the attorney and client. The issue often arises in patent cases as to whether the privilege extends to communications with a U.S. patent agent. Is there a “U.S. patent agent-client” privilege? An even more complex privilege issue involves the privileged status of communications with foreign (i.e. non-U.S.) patent agents. The cases are not uniform in their treatment of whether communications with patent agents (either domestic or foreign) are privileged.
 U.S. Patent Agents
[a] Courts Not Recognizing Privilege
The greater weight of authority strictly, and literally, interpret the “attorney” prong of the attorney-client communication requirement. Those courts reason that because a U.S. patent agent is not a member of the bar of any court, communications between a patent agent and their client are not privileged. Although a patent agent may not be able to create or receive a privileged communications in his own right by virtue of his status, their communications could still be privileged if the agent is acting under the supervision and control of an attorney. In this respect, the U.S. patent agent is treated like any other non-attorney who advises and assists counsel and acts under their supervision and control.
[b]Courts Recognizing Privilege
In the other camp are those district courts that do recognize a form of attorney-client privilege for patent agents, notwithstanding the fact that the agent is not a member of the bar of any court. The rationale behind extending the attorney-client privilege to patent agents is that, as held by the United States Supreme Court, “[t]he preparation and prosecution of patent applications for others constitutes the practice of law.” . . .
In light of the Supreme Court’s recognition that patent agents are authorized to practice law, some courts have reasoned that the recognition of a “patent agent privilege” is simply a logical extension of the Sperry decision. . . . [The author cites a passage from In re Ampicillin Antitrust Litigation.]
Still, it is important to recognize that not all courts agree that the Sperry decision—which was not a case about whether a patent agent enjoys a form of attorney-client privilege—should be read so broadly as to imply a patent agent-client privilege. Thus, it remains an open issue as to whether a U.S. patent agent privilege exists, with cases going both ways on the question.
To the extent that privilege may exist for a patent agent, McCabe explains that it would be limited strictly to "encompass only those services that such agents are legally licensed to perform: i.e., representation in preparing and prosecuting patent applications before the PTO."
Whether you think privilege applies or not, it's wise to always be careful in written communications, email included, recognizing that every word you write may be scrutinized and used against you by a hostile opponent. Save the sensitive, heavy and unpleasant stuff for verbal conversations!