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

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

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