Greasy Fork is available in English.
ymail-basic. DIRECT LINKS TO MUSICBRAINZ
BASIC Yahoo! Mail only (/neo/b/). Adds links to MusicBrainz edits directly in mail.yahoo.com folders view (including "no votes" and "subscription" emails). No need to open all those e-mails any more. Only one link per edit ID, duplicate ID are coloured and e-mail(s) marked for deletion. Once clicked, the link is faded, to keep trace of already browsed edits. Limitations : only Opera(maybe) and y!mail BASIC I guess.