Delta Air Lines is backtracking slightly on changes it previously announced in its frequent-flyer program, but it still plans to reshape SkyMiles to favor big spenders over customers who take the most flights.

Delta outlined the revisions in an email from CEO Ed Bastian to SkyMiles members on Wednesday.

"I have read hundreds of your emails, and what's been most clear to me is how much you love Delta and the disappointment many of you felt by the significance of the changes," Bastian wrote.

The objections focused on the difficulty of achieving elite status and new restrictions on entering airport lounges.

Delta announced the changes in mid-September, saying they were needed to address overcrowding at the lounges and a surge in elite-status customers that was making it harder to score upgrades.

The airline proposed to make spending with Delta the only way to reach elite status — no longer counting flights taken or miles flown. In simplifying the path to status, Delta sharply raised spending requirements for each SkyMiles level.

According to Bastian's email, flights and miles still won't count toward elite status, and spending requirements will go up from current levels — just not as much as they would have under the September changes.

For example, it will take 5,000 "Medallion qualifying dollars" for Silver, the lowest of four levels, down from 6,000 in September. Currently, customers can reach Silver with as few as 3,000 qualifying dollars or points if they take enough Delta flights, and no points if they accumulate enough miles.

The Diamond top tier will cost 28,000 points instead of the 35,000 outlined in September, but more than the current 20,000 plus enough flights.

The changes take effect next year, when travelers will be trying to qualify for elite status in 2025.

Delta also plans to limit the number of times that premium credit card holders can visit airport lounges, but not as severely as it proposed in September.

The September proposal created a backlash among Delta customers on social media, with some threatening to switch to other airlines.

It wasn't just travelers who took notice. JetBlue and Alaska Airlines tried to poach Delta's best customers by offering to match elite status for anyone leaving the Delta loyalty program. Southwest Airlines announced that next year it will make it easier to qualify for the top levels of its frequent-flyer program.

Flyers are a fickle lot, known to switch airlines to save a few bucks on a flight. Airlines design loyalty programs to keep their most lucrative customers coming back.

Henry Harteveldt, a travel analyst at Atmosphere Research Group, said some SkyMiles members will still be unhappy about Delta moving to an entirely spending-based program, and will view even the reduced requirements as too rich.

"I don't think these concessions are going to go far enough to placate the disgruntled Medallions," he said. "Given the mercenary mindset that many travelers have, they will fly other airlines and not look back."

Less than two weeks after Delta announced the SkyMiles overhaul, Bastian announced that the Atlanta-based airline was taking another look at the matter. He said Delta "probably went too far" with the proposed changes.

Last week, Delta officials said on a call with analysts and reporters that the outcry was not affecting signups or spending on its co-branded American Express credit cards.