Delta Air Lines

That's a very strange title given that MS's CEO said that "out of date" meant "not Microsoft".

Fromt the article: On July 24, Microsoft CEO Satya Nadella emailed Bastian as well, according to the letter.

“In fact, it is rapidly becoming apparent that Delta likely refused Microsoft’s help because the IT system it was most having trouble restoring—its crew-tracking and scheduling system—was being serviced by other technology providers, such as IBM, because it runs on those providers’ systems, and not Microsoft Windows or Azure,” the letter said.