SELECT REPLACE(SUBSTRING(convert(varchar, getdate(), 113),0,12),' ','/')+
SUBSTRING(RIGHT(CONVERT(VARCHAR(26), GETDATE(), 109),14),0,6) AS TEST1
SELECT REPLACE(SUBSTRING(convert(varchar, getdate(), 113),0,12),' ','/')+
RIGHT(CONVERT(VARCHAR(26), GETDATE(), 109),14) AS TEST2
--Just replace getdate in above query with
ReceivedMessages.ReceivedDateTime
--TEST1 will give output without AM/PM whereas TEST2 will append AM/PM to the date