You receive an HTTP 500 error when attaching a file over 1MB through OWA.

Conditions
 

• Operating System is Windows 2000/2003
• File being attached is larger than one (1) megabyte (MB).
• If SMSMSE service is stopped then OWA is able to attach files of any size correctly.
• Virus Scanning Application Program Interface (VSAPI) debug log shows the following errors:

Use the following article to obtain a VSAPI debug log: How to obtain a DebugView log file from Symantec Mail Security 6.0 for Microsoft Exchange

Look for entries matching the following:

00000667             6.52655315          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(911) -      
00000668             6.52671814          [3956] fnHandleError with code = -1073217384, param1 = 2080  
00000669             6.52685308          [3956]  
00000670             6.52718973          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(912) -      
00000671             6.52733755          [3956] error reading stream 2080              
00000672             6.52747107          [3956]  
00000673             6.52844143          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(1929) -    
00000674             6.52859402          [3956] Failure copying stream to Shared Memory (-1073217384)              
00000675             6.52874231          [3956]  
00000676             6.52907801          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(2439) -    
00000677             6.52925253          [3956] fnHandleError with code = -1073217377, param1 = 3, param2 =    
00000678             6.52938843          [3956]  
00000679             6.52970695          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(2440) -    
00000680             6.52985716          [3956] Temp file delete failure 3              
00000681             6.52999973          [3956]  
00000682             6.53032255          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(2465) -    
00000683             6.53047180          [3956] VirusScanAndClean error (0x1)    
00000684             6.53060579          [3956]  
00000685             6.53090525          [3956] 2010-02-17 11:20:27 438ms[TID=0xdbc] SAVFMSEVSAPI(2467) -    
00000686             6.53105497          [3956] fnHandleError with code = -1073217391, param1 = 1        

• Operating System has less than 15000 Free Table Page Entries.
    

To check Free Table Page Entries:

1. Open Perfmon.
2. At the top of the page click the plus sign to add a new counter.
3. Under Performance Object select Memory.
4. Under counters select Free System Page Table Entries.
5. Click Add.
6. Click Close.
7. The graph will now display information for the Free System Page Table Entries counter.
8. At the bottom of the page select Free System Page Table Entries.
9. Now the information below the graph (Last, Average, Minimum, etc..) will display data from the Free System Page Table Entries counter.

Exchange is unable to allocate memory for the file scanning process because there are no free page table entries.

The solution requires more free page table entries than are currently available. Use this Microsoft article to determine the cause of the low free page table entries:  The number of free page table entries is low, which can cause system instability.

Symantec recommends implementing and tuning the value of the /userva switch in the boot.ini to allow more Free Page table entries. See How to use the /userva switch with the /3GB switch to tune the User-mode space to a value between 2 GB and 3 GB for details on how to implement and tune the /userva switch.

Note: Symantec makes no specific recommendations about the proper value for the /userva switch. For details on how to implement and tune the /userva switch, see the document above or contact Microsoft support.
 

Workaround

Install S/MIME controls for Internet explorer.  See this link for further details on installing S/MIME controls: http://technet.microsoft.com/en-us/business/support/library/bb124432%28EXCHG.65%29.aspx.

NOTE: Using this workaround only works for Internet Explorer browsers, There is currently no workaround available for Non-Internet Explorer web browsers.

Technical Information

A page table is the data structure used to store the mapping between virtual addresses and physical addresses in memory. The RAM is divided into fixed-size page frames, creating system Page Table Entries to store information about these page frames, and mapping them. System Page Table Entries are small kernel-mode buffers of memory that are used to communicate with the disk I/O subsystem and the network.