X2!
I kept an answering machine recording just in case!
On that recording I was told by the head of a national park that I could use a canoe launch to launch a boat as long as I didn't put the trailer tires in the water, which would be considered a hand launch, a predecessor of his also told me the same thing. One of the head rangers said I couldn't do that and would be issued a citation, it would have been interesting If I had received a citation and played that recording from that head ranger's "boss" at a magistrate's office!
Under the prior head of the park we were confronted by a ranger and were going to get a citation until we told him what his "boss" told us, he got on the phone right away with his "boss", (he thought we were lying), found out we weren't and then started apologizing to us.
Long story, but that's why I also agree with keeping the e mail you got.