Note that the error message tells the user which new address to use ( User has moved to <address> ).The mail system <scpg@arashi.com>: host mail.arashi.com[74.207.241.184] said: 550 5.1.6 <scpg@arashi.com>: Recipient address rejected: User has moved to southern-california-permaculture@permaculture-guilds.org (in reply to RCPT TO command)