As form 8165 says,

"The U.S. Postal Inspection Service is a federal law enforcement agency.

Postal Inspectors gather facts and evidence to determine whether a

violation has occurred under the Mail Fraud or False Representation

Statutes. While the Postal Inspection Service can’t guarantee that [the person had dealings with will] recover money lost to fraud, the information can help alert Inspectors

about new fraud schemes and prevent others from being victimized.

Postal Inspectors base mail fraud investigations on the number,

substance, and pattern of complaints received from the public; therefore,

we ask [that the person making the complaint] keep all original documents relating to [his/her] complaint,

including the solicitation, any mailing envelopes, and canceled checks.

Under our Consumer Protection Program, Postal Inspectors may contact

individuals or businesses on your behalf to request that complaints be

resolved."

I suspect that nothing will come of this. If postal inspectors do contact you, you should refuse to answer any questions they may have without having an attorney present during questioning.