Starting 14:30 UTC today I'll move our mailing lists to a new server. Expected downtime is 2 hours.
This post will be updated once the move is done.
Update: Migration complete, sorry for the couple mails with the wrong List-Id, I've corrected that now. If you experience any other problems with the mailing lists please feel free to send me an email (postmaster@archlinux.org) or ping me on IRC.