The export process to the .pst files very slow with New-MailboxExportRequest

Not open for further replies.


We are upgrading Exchange 2010 to SP1 and a new possibility export mailboxes to .pst file (without outlook) ( New-MailboxExportRequest) is very slow. After the queue checking (Get-MailboxExportRequest) we recognized the process works only 5 threads and realy very very slow. Maxthreads option does not exist.
Any help would be appreciated.


I have the exact same problem, been running a overnight script that queues up the mailboxes for export. When i check my logs in the morning only about 6 mailboxes export successfully.

Found this article which indicates the replication service is causing problems with mailbox moves. Wonder if there is any reason this could be slowing down or failing exports using the new sp1 commands.

If anyone else has any ideas on how to get the new sp1 exports working im all ears.

In regard to the maxthread option have a look at this article for a workaround.

Brian Desmond -MVP-


There may be some settings for concurrency in the config file for the MRS - Look in the bin folder under your Exchange install for the MSExchangeMailboxReplicationService.exe.config file (might be called something slightly different). My limited experience is that this process is resource intensive and not particuarly speedy but it's also typically not something you do alot of or en-masse. Keep in mind that the storage you're writing to needs to be able to keep up and that every CAS server in the site will participate so you can get some concurrency there.

My Book - Active Directory, 4th Edition
My Blog -

Brian Day MCITP

Are you using a CAS array that goes through any kind of hardware load balancer? If so, what make/model is it?Microsoft Premier Field Engineer, Exchange
MCSA 2000/2003, CCNA
MCITP: Enterprise Messaging Administrator 2010
Former Microsoft MVP, Exchange Server
My posts are provided "AS IS" with no guarantees, no warranties, and they confer no rights.


Hi Brian and Brian :)
I changed MSExchangeMailboxReplicationService.exe.config values from default to:
MaxActiveMovesPerSourceMDB = " 50"
MaxActiveMovesPerTargetMDB = " 50"
MaxActiveMovesPerSourceServer = " 50"
MaxActiveMovesPerTargetServer = " 50"
MaxTotalMovesPerMRS = " 100"

but there is no change unfortunately, 5 mailboxes are in the queue. Certainly I restart mailboxreplication service.

We don't use any hardware load balancer, we are running a simple storage volume.

thank you in advance


We also have recognized this problem.
One look at our resource monitor shows a disk queue length of 5 and higher on the target server while the export script runs. So, it seems to me this is a bottleneck of the disk i/o or in other words, the replication is not optimized for it. We also recognized that it doesn't matter which kind of disk subsystem is used. We could see this behavior on normal sata disks as well as on a RAID 6 volume with round about 1500 IOPS.
I hope someone have an idea for this. Any ideas, hints oder solutions are appreciated.



On further investigations, the " System" process is responsible for the high iops count. I did a complete clean installation with integrated sp1. No differences.

I will make further researches, but if someone can agree to my researches or results, please let me know.
Not open for further replies.
Thread starter Similar threads Forum Replies Date
K Disabling import/export button to restrict PST creation Using Outlook 3
K Export Folder to PST Outlook VBA and Custom Forms 2
R Outlook 2010 How do you export 2 email Accounts' 2010 Inbox Files to new computer (2019)? Using Outlook 0
O Export Outlook calendar appointments by filters and date range Outlook VBA and Custom Forms 1
M Export-Import .pst file problems Using Outlook 2
M How to export Voting Results with user names and their responses Outlook VBA and Custom Forms 13
J Export Zimbra to Outlook PST Using accounts in Outlook 1
S How to export urls from email to excel and check the status of the url ? New Articles 6
C Export NSF Lotus Notes files in Outlook PST format? Using Outlook 1
C How to export Outlook data to csv? Using Outlook 0
T How to Export mailbox from Outlook 2019 to MBOX format? Using Outlook 1
M Auto-export mail to Excel Outlook VBA and Custom Forms 2
P How to export voting results using VBA? Outlook VBA and Custom Forms 2
R How To Repair OST File & Export OST File to Outlook PST ? Using Outlook 3
JohnViuf Export task list view settings to other pc Outlook VBA and Custom Forms 16
J Copy or Export Outlook Mail to Excel Outlook VBA and Custom Forms 6
N Export details to a excel spreadsheet using macros Using Outlook 0
avant-guvnor Export Calendar, Birthdays and Holidays Outlook VBA and Custom Forms 0
Diane Poremsky Export (Save) Outlook Contact photos New Articles 0
K Macro to search emails between two time slots on public folders with excel export Outlook VBA and Custom Forms 12
A How to export one email data to excel Using Outlook 1
B Macro To Create Rule To Export From Certain Folder Email Information in one workbook multiple sheets Outlook VBA and Custom Forms 0
W macro to export outlook emails to excel Outlook VBA and Custom Forms 6
E Exchanger service export detection Exchange Server Administration 1
R Correct a wrong csv export file from WLM 2012 Using Outlook 0
Q Outlook 2016\365 export specific rules to import in another system Exchange Server Administration 1
H How to export *all* fields from Outlook Using Outlook 2
K Export Organizational Forms Library Exchange Server Administration 1
N Export Outlook custom forms fields to excel Outlook VBA and Custom Forms 1
E RSS export as OPML problem Using Outlook 4
A export free / busy from exchange Exchange Server Administration 0
C Export to excel missing items, but a larger total? BCM (Business Contact Manager) 6
M Outlook 2013/365 won't export 99% of my contacts to csv Using Outlook 2
T Outlook 2007 Export tasks to Excel Using Outlook 2
J Opening/Archiving/Import/Export PST files Using Outlook 4
H Select one of Contact-Mailadesses to Export > Excel or Winword Outlook VBA and Custom Forms 2
Sarge USMC Cannot import/export Outlook 13 Using Outlook 6
L Outlook 2007 Codes Export and Import Using Outlook 9
L Outlook 2007 Toolbar Export and Import Using Outlook 7
S Requried a VBA Code to export Calander details to excel... Outlook VBA and Custom Forms 4
Jennifer Murphy Can I export individual emails? Using Outlook 1
R Export Address Book VBA Using Outlook 0
W How to export additional fields in contacts Using Outlook 1
R Recover/export rules from a backup .PST Using Outlook 2
J Formatting Contacts to Export for iPhone Using Outlook 0
B No export way Using Outlook 4
F Export Outlook contacts by One Category Using Outlook 1
Jennifer Murphy Difference between export and archive? Using Outlook 10
J How can I EXPORT my email address bok? Using Outlook 1
D Macro to export mail data based on assigned category Using Outlook 3
Similar threads