Named Props Quota in Exchange 2007, SP1 RU8 and beyond
Ratish post here has already detailed about Named Props Quota and the trouble it creates for the Admins in Exchange 2003 and 2007 and so, I am not going to dive into it now. But the good news is that Exchange 2007 SP1 RU7 and Exchange 2007 SP2 has got in some improvements, but at the same time, not with problems.
Most of us would have seen the scenarios where we start looking for a fix for this the moment our Exchange server starts warning us. Few of us would have started searching for a better boss when the limit reaches max and get stuck there. 🙂
In Exchange 2007 and Exchange 2003, we have seen x-headers finding a place in Named Props Quota table. Few of us might have even used Header Filter Agent available for download in Codeplex for Exchange 2007 post SP1, to strip the x-headers on the transport level. Exchange 2007 SP1 changed this behaviour to NDR an e-mail only when a non x-header named props quota was not mapped in the table even though the quota limit is reached. RU8 for SP1 makes sure that an non-authenticated message does not create an entry in the table.
SP2 for Exchange 2007 makes the store behave the Exchange 2010 way (only w.r.t Named Props Quota table). The scenario becomes worst for x-headers in case of even authenticated messages. They find their place in PR_TRANSPORT_HEADERS property of the Mailbox, but no place in NPQ table of the database.
So, how will it affect me?
You’re unlucky if your users use IMAP clients. Post Exchange 2007, we have no more STM files and if you are not aware of, IMAP clients uses these headers to search for messages which will be lost. Head to Jason Nelson’s post in MSExchangeTeam.com to know about this in detail and most important, they want to hear your voice about this change there.
How about if I’m using Exchange 2003?
Sorry to keep it last, but there is a Hot Fix released by Microsoft with the help of which, you can control the generation of new entry in the table.
REMEMBER, NONE OF THESE HAVE INCREASED THE NAMED PROPS QUOTA LIMIT AND STILL REMAINS 32768. So, if you want to ignore the 9667 warnings, better get ready for a new job!