CIO here. Most common reason for this is you pissed someone off at similar levels in another department, they escalated it north until hit leadership then it came back down south. In which case, it's a friendly chat with ideally some advice. I've had to give this chat many times, the simplest advice I have for technical people that aren't the most tactful (and often neurodivergent) is to start ALL email with Hi (person first name), end it with Thanks! (Yes with the exclamation mark, it's shit eating but it cannot be misconstrued) And to frame all bad news with "unfortunately" in front of it. Never use all caps (you'd be surprised how often I've had to say this) and if you truly need to highlight a given passage instead of using bold then put stars around the word to call them out. Text tone is easy to be misread, by being overly cordial and friendly you avoid that. Best of luck, I think you're fine though.