Are e-mail and phone records able to be subpeonaed in a probate/divorce matter?
Yes. If the records are potentially relevant, they can be subpoenaed. For example, if the third party is the alleged lover of the spouse, then those records can be obtained.
Lawsuit / Dispute Attorney
While it may be possible, it is likely that a motion to quash the subpoena will and should be filed. You will need to give notice to the other party before issuing a subpoena, so this cannot be done behind there back if that is desired.
In reality, since no cause is needed for a divorce in Mass, the courts will want a good reason to allow such inquiries.
DISCLAIMER: This answer is provided in response to a "hypothetical" question and provided for general, informational purposes and does not create an attorney/client relationship. The information presented is not legal advice and may change based additional information and research. It is recommended that you speak to an attorney to discuss your specific legal issues.