+ if not domain_exists(domain_to)
+ msg = "destination domain #{domain_to} does not exist"
+ raise NonexistentDomainError.new(msg)
+ end
+
+ mailbox_query = 'UPDATE mailbox SET '
+ mailbox_query += ' username=$1,'
+ mailbox_query += ' domain=$2,'
+ mailbox_query += " maildir=CONCAT($2, '/', $3, '/'),"
+ mailbox_query += ' local_part=$3 '
+ mailbox_query += 'WHERE username=$4;'