Members in your projects can see your email address in the project member list; viewers in your project cannot (for more on project member roles see Project member roles).
If you are a project owner, account owner, or account admin, you can see the email address of anyone in the project or account in the project member list, account member list, or when inviting new members via autocomplete.
This balances privacy and usability. For instance, when you’re inviting someone to a project by email address, the autocomplete field will suggest someone who’s on another of your projects, but it won’t let you browse the entire universe of email addresses known to Tracker.
If you need more privacy, a project owner, account owner, or account admin can select Hide email addresses in Project Settings. This setting will allow only the project owner, account owner, or account admin to see email addresses in the project’s member list. It also means that, when inviting new members to other projects, the email addresses of anyone in the “hidden emails” project will not be autocompleted (unless that person is also invited to projects that do not have Hide email addresses selected).