I believe the official ruling is "we can't prove that you did not get the information elsewhere, so it's not against the rules." Roleplays should be considered public information to everyone who received it. If you don't want many people to find out, send it to a narrower message channel.
So, be prepared to be accused of eavesdropping, which might carrying IC consequences. You won't get hit with an OOC ban or anything like that.
I'd say producing a copy of a roleplay message would still be gauche though. Act on the information, but be prepared with a reason/excuse on how you got it.
