OneDev needs to mark unverified email, as not doing so can impose security issues:

1. User adds an unverified email of other staff (email not currently used in OneDev)
2. User configures local git to use that email for commit authoring
3. User configures PGP signing of the commit
4. When the commit is pushed to OneDev, the commit is displayed as signed commit using that email to get trust.

Then it needs a separete option for private email. You configure the noreply domain in the admin settings, and it is automatically assigned to the user.

State changed as build OD-8064 is successful

Thinking about why gitea and github private email contain a number before the email address, I think it is the user ID (for example github ID can be check with the API: https://api.github.com/users/zarpyk and is the same number, on gitea I think I'm just the user number 1), so if you change the login name, other people can't get you noreply email.

With the current implementation, if you change your login name, the noreply email become available for anyone that get your old login name? I don't know how GPG key works exactly.

OneDev intentionally does not prepend user id as that can lead to all git commits incorrectly associating with incorrect user if you import the repository into another OneDev instance (or other git hosting software such as Gitea) which may use different user id for same login.

Changing login name can be a problem, and we should avoid changing login name in normal cases. I think this is a common limitation for many systems.