ALTER TABLE
  ident_switch
CHANGE
  host
  imap_host varchar(64);

ALTER TABLE
  ident_switch
CHANGE
  port
  imap_port int;

ALTER TABLE
  ident_switch
ADD COLUMN
	smtp_host
    varchar(64);

ALTER TABLE
  ident_switch
ADD COLUMN
  smtp_port
		int
		CHECK(smtp_port > 0 AND smtp_port <= 65535);

ALTER TABLE
  ident_switch
DROP COLUMN
  delimiter;