CrowdStrike's contractual liability is capped in the single-digit millions, the letter said. Delta did not comment on the letter on Sunday night. In a separate statement, CrowdStrike said it hopes "Delta will agree to work cooperatively to find a resolution." "We did everything we could to take care of our customers over that time frame," Bastian said in an interview Wednesday on CNBC's "Squawk Box." "If you're going to be having access, priority access, to the Delta ecosystem in terms of technology, you've got to test this stuff. You can't come into a mission critical 24/7 operation and tell us we have a bug. It doesn't work." CrowdStrike vowed to release future software updates in stages in a preliminary post-incident report. On July 30, CrowdStrike shareholders filed a suit against the company in a Texas federal court and sought damages for declines in their investments. CrowdStrike reports fiscal second-quarter results Aug. 28.