"Hide My Email" reply exposes personal iCloud email address instead

I just tested this by sending from one of my other accounts and that was not the case. If you have set your emails to automatically cc: your actual account at Mail > Settings > Composing, then your email address will be included.

Unaha-Closp wrote:

Do you have "send new messages from" set to a specific account or to "automatically select the best account"? That setting shouldn't override this privacy-focused feature, but it's something to consider perhaps.

I have send new messages set to "automatically select the best account".

The link you provided saying it was a consistent issue does not show that at all. Most of the posts in that link are about how to use Hide My Email or how to shut it off. There are a few posts, but one claims they are using Mac OS 11 and cite that reason along with a link showing Mac OS 12 is needed and the others don't provide any follow up so it is unclear if they found an answer or just gave up. With so many people using Hide My Email, I would expect this site to be filled with that same issue.

Sorry I can't be more helpful, all I can do is test on my end to see if the same thing happens to me. I am using Mac OS 15.1, but not sure if that makes a difference. Without anyone else jumping in with the same issue or encountered it and found a solution, I all can recommend is to contact Apple directly. I am willing to offer any help I can to confirm any settings that may be different or any tests I can perform. The only other difference I can think of is my Apple ID email address is not an iCloud address, so don't know if that matters either.

Contact Apple for support and service - Apple Support

If you end up contacting Apple, please update with any information you find out and hopefully a solution.