I suppose (I'm no legal eagle so don't count on me for this) depending on the severity, they COULD sue for slander?
If someone had sent an email out saying "so and so is only moving us to a new office so that he gets 100k in his back pocket" you're basically accusing him of embezzling money to however many people that are in the conversation. If that gets forwarded on to other people maybe not in the company (ie you or us!) it could be seen as purposefully damaging the name of the individual or the company.
Taken from some random website:
"You can prove defamation on your word alone, even though it is always better to have some confirming evidence. (a letter, a memo, an e-mail, statements from fellow employees confirming the defamatory remarks about you, etc.) You can testify in court as to statements made by others about you. This means that the "hearsay" rule does not apply to the testimony in court which repeats defamatory statements.made out of court.
You do not have to prove damages in defamation cases. Damages are presumed. This means that you do not have to testify that you were emotionally destroyed or had to see a psychiatrist or other mental health specialist or doctor."
I think you'd have to come across a nasty judge for this to happen, but people have been given massive punishments for smaller things on places like twatter. Suppose it all depends on how many people were involved and how nasty the individuals who feel aggravated by it.