When analyzing the UMPoll.EWSPoll.log, you observe that the same emails in a particular mailbox and folder are being processed in each cycle over and over again.

For example:

• 1st Cycle:
  
  

  2012-07-03,15:45:13,176,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","Processing mailbox: user@domain.com" 
  2012-07-03,15:45:14,045,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","Processing \\\Sent Items" 
  2012-07-03,15:45:16,591,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","New <4C47CBA8F6BB444A9FEE6E1A476D20B7012886@mailserver.domain.com>" *** exactly 7000 emails are being processed here *** 
  2012-07-03,15:52:52,694,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","New <4C47CBA8F6BB444A9FEE6E1A476D20B711AA45@mailserver.domain.com>" 

• 2nd Cycle:
  
  

  2012-07-03,15:56:50,109,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","Processing mailbox: user@domain.com" 
  2012-07-03,15:56:50,964,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","Processing \\\Sent Items" 
  2012-07-03,15:56:53,587,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","New <4C47CBA8F6BB444A9FEE6E1A476D20B7012886@mailserver.domain.com>" *** the exact same 7000 emails are being processed here once again*** 
  2012-07-03,16:04:30,282,1,"#00003990","#00000004","info ","UMPoll.EWSPoll","New <4C47CBA8F6BB444A9FEE6E1A476D20B711AA45@mailserver.domain.com>" 

Further cycles will show the exact same emails being processed again.

• Generally, only emails that have been moved or have been created in the folder should be processed and listed in this log file to compare them between cycles.

• A useful indicator for this behavior can be found when analyzing the ..\MailArchiver\Core\UMPolling\UMPollingStatus.xml file.

  XML Marker and the easy-to-read table view help in identifying repeat cycles.

• Look out for any users which show high and rounded numbers (e.g., 1500 or 3000) in the element.

  Notes: In the reference case, some email headers (Subject, From) did contain the special character -. Outlook displays the character in question as a square (a place holder character itself).

Fixed in MARC2014 build 20140616

Fix Details

Implemented a safe mode mechanism that works as follows:

1. As soon as a batch containing a corrupt item is found, the batch size is reduced to 1 and restarted.

2. Once the call fails, we have found the point at which synchronization fails.

3. We switch off XML validation to allow the item to be returned by EWS and processed by UMPolling and switch it back on.

4. We then resume normal batch size synchronization.

5. Safe mode will be reverted after X single requests have been made in safe mode, and the invalid item is not found (X is the number of items in a normal mode batch request). 

Workaround:

1. Look through the affected folder via Outlook / OWA to identify the email in question (look out for place holder characters like a square in common headers like Subject, From, To, CC).

2. Move the affected email(s) to a subfolder.

3. Exclude the subfolder with the problematic emails from UMPolling by adding a matching policy under Configuration > Mailbox Folder Structure Retrieval > Excluded Folder Policies.