Thus it would safe to assume that Fox News, CNN, and MNBC are more along the lines of opinion-oriented news outlets compared to PBS News.

News reporters and writers (unless doing an editorial) should remain purely objective or as Jack Webb used to say on Dragnet, "Just the facts ma'am."

Anything else (unless pre-defined as an opinion piece) is fake news and no one really cares about the personal opinions of news reporters and correspondents.

Opinions

I'd take the emails with a grain of salt. Most of us understand the difference between a news report, opinion piece and misinformation. The media is an easy target.

Journalists should remain objective but they're human. We all have biases, and they'll show.

Walter Cronkite (the most trusted man in America) let his liberal bias show. This was way before cable news, and I was a kid. If a kid could see through his biases, I'm sure adults could.

I trust any media organization that passes "fact-checking." I believe Embarcadero Media would pass.

The cable network that I occasionally watch does disclose that it is opinion rather than news. And currently I do not think there is a single source of "news" that does not have some bias, which would include the subject matter reported. Sources would include CNN, Fox, Microsoft News and PBS. And don't forget newspapers either.
Exceptions are reporting of major real life events such as 9-11 or the Challenger disaster from the past.