Index rebuilding repeatedly

I am using MailStore Home on Windows 10
When I launch the application, it opens a window saying “Rebuilding search index” and initiates a rebuild of the index. When the rebuild completes, the application works as expected.

However, when I terminate the application and then restart, the index rebuilding (which is time consuming) restarts anew.

Help will be appreciated.

Hello @slevis,

it seems the index looks defective on every startup, so it needs to be rebuilt.

Could there be any third party service or program interfering?

Please check the following:

  • Antivirus/Security software - are there any log entries or quarantine informations that files have been blocked, recovered or isolated? Please exclude your archive folder from scanning, as it is active database technology
  • Cloud solutions - do you have any cloud solutions installed (OneDrive, Dropbox or similar) that monitor your documents folder and automatically upload files? Please exclude the archive folder, as the database technology does not like parallel copy operations on its active files
  • Backup software - do you have backup software that does pure file copy operations? The same issue from cloud services also applies here

Hi, I have a similar problem with the search index - I added pdf to the search parameters and MStore obviously needs to rebuild the index.
For several days now I have let the rebuild run for 10 hours or more - but each time I need to shutdown and restart it seems to start from scratch?
Is this correct?

Hi @GeorgeH,

have you enabled PDF indexing and installed the PDF iFilter from Adobe as described in this help article?

If so, did you see the paragraph hinting a special action to be taken with the Adobe filter?

Important Notices:

* Take note of the installation instructions (
of the 64bit IFilter. Especially adding the  *bin*  folder of the IFilter installation folder to the  
*PATH*  system variable increases indexing speed a lot. The  *PATH*  system variable can be adjusted as administrator via 
windows key + R
rundll32 sysdm.cpl,EditEnvironmentVariables  

If not, on some systems, the iFilter runs very slow or even times out in the background, resulting in a lag of up to one minute per mail containing PDF(s).


Many thanks - this is a new laptop and I will check Adobe iFilter and let you know.

1 Like

Done - worked well. Rebuilt in approx 90 mins.
I found this “plain English” version of the instructions in the text.rtf file:

Installation Notes

1.Download and extract contents of “” to your local drive.

2.Double click on ‘PDFFilter64installer.msi” to launch the installer.

3.Follow the instructions in the installer wizard to complete the installation.

  1. After installing the PDF IFilter it is recommended that you set your system PATH environment variable to ‘bin’ folder of ‘Ifilter’ installation.

e.g. From the ‘Control Panel\System\Advanced\Environment Variables’ tab, append to PATH:

C:\Program Files\Adobe\Adobe PDF iFilter 11 for 64-bit platforms\bin\

and then restart the machine.


Hi @GeorgeH,

that describes the step I mentioned earlier in different words and paths,
yes, it is important to add the Adobe iFilter to the system path variable,
they have decided to not do this automatically via installer.

Hi All,
needs some assistance with the pdf ifilter.
Since installing and changing the system path variable the indexing is taking weeks to progress and is at this stage unable to complete without crashing.
I do have a rather large store of 950 k messages which is 128,312 mb in size.
I want to ensure that i have the correct details in the System variable environment.

Please see below screen gras.



I am super grateful for any assistance you may be able to offer.


Hello @Jsmail,

I am a little confused why you added a new system variable “Adobe iFilter”.

There is already a system variable “PATH” which needs an additional entry to the install path of the iFilter bin folder.

1 Like

Hi There George,
Appreciate your assistance here.

Just so I am 100% clear

  • List item

I did add in an additional entry that i called Adobe ifilter, and you are sayi ng this is incorrect and i should delete this.

  • List item
    I should amend the exist entry called Path from what it is currently noted as
    "C:\Program Files (x86)\Intel\iCLS Client;C:\Program Files\Intel\iCLS Client;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0;C:\Program Files\Intel\Intel® Management Engine Components\DAL;C:\Program Files\Intel\Intel® Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel® Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel® Management Engine Components\IPT;C:\Program Files (x86)\QuickTime\QTSystem;C:\Program Files (x86)\Skype\Phone;C:\Program Files (x86)\Intel\UCRT;C:\Program Files\Intel\UCRT;C:\Program Files\Intel\WiFi\bin;C:\Program Files\Common Files\Intel\WirelessCommon
    and i should add on C:\Program Files\Adobe\Adobe PDF iFilter 11 for 64-bit platforms\bin. Is this correct?

I really appreciate your assistance.

Hi @Jsmail,

Windows 10 offers to add a line in a list of items, where earlier versions just show a list like yours.
In case of that list, add a semicolon (";") and then the additional iFilter path to the end of that already filled PATH string,

so “…WirelessCommon;C:\Program Files\Adobe\Adobe PDF iFilter 11 for 64-bit platforms\bin”


Thanks very much