I also am experiencing the problem that wiki.musicbrainz.org can’t seem to confirm email addresses (see topic Wiki cannot confirm my email address, Sept 2017). This appears to be tracked by ticket OTHER-259: MB wiki fails to send mails for address verification, opened in Oct 2016 and encountered again (MBH-501) in July 2018.
Could a sysadmin perhaps look at this and post an update in OTHER-259?
Thank you,
—Jim DeLaHunt, Vancouver, Canada