You can’t read every email that drops into your inbox. There are just too many. So publicists have learned how to attract attention.

On Monday morning, the following press release appeared in my inbox with a ping. It was not made up. It was not spam. It was from MSNBC, and it announced the results of a major investigation by NBC News.

It was headlined “NBC News Report: ‘Donald Trump Does Not Have a Campaign.'”

Which was kind of a surprise. Trump has a campaign plane and campaign rallies and a campaign press corps, so why doesn’t he have a campaign?

It’s like owning a Rolls-Royce and never driving it.

The press release began, “According to a new Decision 2016 NBC News report headlined ‘Donald Trump does not have a campaign,’ Donald Trump is a candidate without a campaign — and it’s becoming a serious problem.”

(The press release could just as easily have begun by stating that “NBC News does not have a person who knows how to write press releases,” but I don’t want to be snarky.)

The report says:

“Republicans working to elect Trump describe a bare-bones effort debilitated by infighting, a lack of staff to carry out basic functions, minimal coordination with allies and a message that’s prisoner to Trump’s momentary whims.

“‘Bottom line, you can hire all the top people in the world, but to what end? Trump does what he wants,’ a source close to the campaign said.”

I know it is shocking to have a candidate who “does what he wants,” but the alternative is to have dimwit staff members doing what they want.

True, Trump presents serious problems as a candidate. He’s a bigot. He does not understand world affairs. And he does not understand domestic affairs.

But that is not the problem, according to his staff. The problem is that Trump has “a message that’s prisoner to Trump’s momentary whims” instead of being prisoner to his staff’s momentary whims.

That raises a question: If Trump is such a bad campaigner and “does not have a campaign,” how has he done so well?

Trump locked up the Republican nomination in late May, while Hillary Clinton — who has a staff the size of Sacramento — was still struggling to lock up her nomination.

The NBC News report also severely criticizes Trump’s handling of the Trump University scandal.

The report says:

“Aides appeared unprepared for the Trump University story last week, despite knowing in advance that unsealed court documents would reveal explosive allegations of fraud. Beyond a short video of former students praising the program that was posted online, the campaign offered scant pushback.

“The absence of a response to the Trump U story left the candidate to fill the vacuum with a torrent of demagoguery against the federal judge overseeing the case, Gonzalo Curiel, who Trump said was biased by his ‘Mexican heritage’ despite his Indiana birthplace.”

But if Trump had a huge staff, could that staff have prevented him from unleashing “a torrent of demagoguery”? Yes — if it wrapped him in a torrent of duct tape.

The report does throw Trump a few bones: “Despite the campaign’s sluggish start, Trump supporters stressed that his unique gifts, especially his ability to command media attention via Twitter and cable news, give him some leeway to bypass ordinary campaign methods. They also are encouraged by polls that show Trump competitive with likely Democratic rival Hillary Clinton and Republican voters largely united despite the bruising primary.”

That is another way of saying, “Hey, this guy is a complete tool, but he’s awfully good at it.”

And in fact, Trump sent out a tweet that shows how deft he is at social media (despite the usual typos): “I am getting bad marks from certain pundits because I have a small campaign staff. But small is good, flexible, save money and number one!”

NBC News thinks Trump should seek other sources of wisdom, including aides from other past campaigns. Remember that terrific Mitt Romney campaign of 2012, for instance?

The report says, “The Romney campaign, for example, helped push coverage of Obama’s ‘You didn’t build that’ quote by organizing events with supporters in the business community in swing states around the country.”

I see one problem with that analysis, however. The “You didn’t build that” attack was exceptionally stupid and ineffective, even by Romney campaign standards.

But do not despair. “The good news for Trump is that it can only get better from here,” NBC News concludes.

That’s true. All the Trump campaign needs to do is hire a top adviser to answer criticism with erudite, eloquent, articulate and persuasive responses.

Anybody know what Sarah Palin is doing these days?

Roger Simon is Politico’s chief political columnist. His new e-book, “Reckoning: Campaign 2012 and the Fight for the Soul of America,” can be found on Amazon.com, BN.com and iTunes.

Photo: Republican U.S. presidential candidate Donald Trump speaks during a campaign rally in Lynden, Washington, U.S., May 7, 2016. REUTERS/Jim Urquhart