If a person was talking to an undercover police officer and never used the actual names of something

It was an email and text conversation until he went to them.

There isn't enough information in your question to provide a very specific answer.. What gives police officers a case and a conviction is very seldom one single item of evidence. Most often it is a combination of a lot of different things. If the information in the email lines up with other evidence, it may be useful to the police although it wasn't specific enough to stand on it's own. It's like putting together a puzzle. If all of the pieces fit, each piece is valuable in providing the complete picture.

If u did not give real names then the entire story might be invalid in court unless u give well known nick names