The suspicious letter that sent President Donald Trump’s daughter-in-law to a Manhattan hospital was postmarked from Boston and appeared to contain corn starch, multiple senior law enforcement officials told NBC News.

The letter was addressed to Vanessa Trump’s husband, Donald Trump Jr., the president’s eldest son, officials said.

The Trump family expressed disgust over the Monday incident.

“No one deserves to be frightened this way,” Donald Jr.’s sister Ivanka tweeted.

Donald Trump Jr. called it “disgusting” in a tweet but said everyone was safe.

Vanessa Trump and two other people were taken to New York Presbyterian-Weill Cornell Medical Center strictly as a precaution.

The NYPD said the white powder in the envelope was deemed to be non-hazardous and was taken to a lab for further analysis. More testing is being done, but officials said it appeared…