alternate to IF EXISTS ..UPDATE ELSE ..INSERT

USE master 
DECLARE @status INT,
        @MsgID VARCHAR(255),
        @msg_id VARCHAR(255) 
DECLARE @status2 INT 
DECLARE @message VARCHAR(8000),
        @dateRecive VARCHAR(255),
        @subject VARCHAR(255) 
DECLARE @subjectMessage VARCHAR(255),
        @unread VARCHAR(5),
        @UnreadFlag VARCHAR(5) 
DECLARE @originator_address VARCHAR(255),
        @SentBy VARCHAR(255) 
DECLARE @i INT 
DECLARE @attachments VARCHAR(255),
        @attachmentsMessage VARCHAR(255) 


EXEC @status2 = xp_findnextmsg @msg_id = @MsgID OUTPUT 


WHILE @MsgID IS NOT NULL
BEGIN 
    EXEC @status = xp_readmail @msg_id = @MsgID ,
         @originator_address = @SentBy OUTPUT ,
         @unread = @UnreadFlag OUTPUT , @message = @message OUTPUT ,
         @date_received = @dateRecive OUTPUT ,
         @subject = @subjectMessage OUTPUT ,
         @attachments = @attachmentsMessage OUTPUT 


    SELECT @message ,@dateRecive ,@subjectMessage ,@UnreadFlag ,@SentBy ,@attachmentsMessage 
    EXEC @status2 = xp_findnextmsg @msg_id = @MsgID OUTPUT 

END