IF NOT EXISTS(SELECT * FROM sys.columns WHERE object_id = OBJECT_ID(N'[dbo].[CSAPP_SUPPORT_MAIL]')
AND name = 'TITLE')
ALTER TABLE CSAPP_SUPPORT_MAIL ADD TITLE VARCHAR(255) NULL

IF NOT EXISTS(SELECT * FROM sys.columns WHERE object_id = OBJECT_ID(N'[dbo].[CSAPP_SUPPORT_MAIL]')
AND name = 'TIMESTAMP')
ALTER TABLE CSAPP_SUPPORT_MAIL ADD MAIL_DATE DATETIME NULL

IF NOT EXISTS(SELECT * FROM sys.columns WHERE object_id = OBJECT_ID(N'[dbo].[CSAPP_SUPPORT_MAIL]')
AND name = 'CUSTOMER')
ALTER TABLE CSAPP_SUPPORT_MAIL ADD CUSTOMER  VARCHAR(255) NULL

IF NOT EXISTS(SELECT * FROM sys.columns WHERE object_id = OBJECT_ID(N'[dbo].[CSAPP_SUPPORT_MAIL]')
AND name = 'CRent_USER')
ALTER TABLE CSAPP_SUPPORT_MAIL ADD CRent_USER VARCHAR(255) NULL