This plugin lets users log into ikiwiki using any email address. To complete the login, a one-time-use link is emailed to the user, and they can simply open that link in their browser.
Users who have logged in using emailauth will have their email address used as their username. In places where the username is displayed, like the RecentChanges page, the domain will be omitted, to avoid exposing the user's email address. In places where the full username needs to be put, like commits of changes, the email address is cloaked using the foaf:mbox_sha1sum spec.
This plugin needs the Mail::Sendmail perl module installed, and able to send outgoing email.