Annoying backfill requests

[Shad007]

Hi all, not really considered an exchange guru but i've managed to set up and integrate a couple of 2010 exchange servers (VM's) and integrated them into our existing routing group. Everything is running smoothly except i can't migrate ppl over to 2K10 yet until i fix this annoying backfill request problem. It seems that some public folder settings i've missed are still trying to replicate from 2K10 back to 2K3 servers. Im pretty sure i've disabled all replication however they keep appearing in the msg queue. Im receiving public folder msgs in the 2010 queue that indicate the sender does not have permission to send the email. Realistically speaking I will be decommissioning the 2K3 boxes once everyone has been cutover so i want to stop all replication going from 2K10 to 2K3...2K3 to 2K10 is OK however not required.

Any suggestions?

 

[Shad007]

ok, no answers yet. Based on the confusing question above im not surprised

Attempt at explanation #2:

I have publicfolder messages stuck in the 2010 queue that are trying to push PF replication back to my 2003 servers and returning a 454 5.7.3 Client does not have permission to Send As this sender error.

Does anyone have any idea what part of the microsoft exchange maze i need to be looking at to give permission to my 2003 boxes to allow replication back from 2010 servers? or is this not possible due to the differences in the schema?...if not possible how can i totally disable public folder replication from 2010 back to 2003?