Etiquettte wise if somebody starts a unsolicited, unwanted private converstion with you, I dont see any problems with making it public.
If on the other hand, you start conversing with the person privately then it would be wrong to "air the laundry" without their permission.
Lastly, if you are conversing with a person privately and then you tell them to stop bothering you but they don't, I would consider all e-mails past that point to be fair game for public airing.
That being said, you should have posted under chat....
