Staff aren't thrilled about having to read demeaning comments about their appearance, weight and even their sexual orientation throughout their work day.
Here are some more examples of real messages they have received:
"The aisles are too narrow on your planes and my elbows kept getting bumped by the pudgy flight attendant who couldn't control the movement of her ass."
"Ugliest flight attendant I've ever had but she was sweet."
"I think the red dresses worn by your flight attendants look horrible. They are skin-tight and completely unflattering."
The airline says it's currently adjusting filters to prevent such inappropriate comments making their way through to the crew.
Delta spokesperson Allison Ausband talked about the program recently, saying: "This is a new system and we'll continue to work together to make it the best feedback mechanism for all of us, so keep the feedback coming; and I apologise for any comments you've seen or might see that aren't intended to make us better."
news.com.au has contacted Delta for further comment.