My book might mention the RPC limit but it's strictly an Exchange setting 
 
that's controlled by a registry setting on the server. It limits how many 
 
RPC channels any application can open at any one time so as not to bog down 
 
the server. Since the setting can be anything if the admins change the 
 
default, all you really need to understand is to follow best practices and 
 
release your objects as soon as they are not needed and not to create 
 
intrinsic object variables by using compound dot operators, especially 
 
within loops where the objects will persist until the procedure running the 
 
loop has ended. 
 
I don't understand your question about folder browsing. Just use a recursive 
 
procedure that digs into each MAPIFolder.Folders collection, starting with 
 
the NameSpace.Folders collection or at a selected starting point. 
 
"Richard Elgert" <relgert[at]tct-inc[dot]com> wrote in message 
 
news:Ob4mT6y7JHA.4100@TK2MSFTNGP06.phx.gbl... 
>  retValue =  System.Runtime.InteropServices.Marshal.ReleaseComObject(oMsg ) 
>                 GC.Collect() 
 
>  OK I did add the above 2 lines and the 250 limit error is gone.... but I 
>  am not sure I fully understand... (will your book clarify) 
 
>  and a follow up, I need to browse all folders and sub-folders in a users 
>  mailbox. .