citrix, outlook, desktops

Where is the OST being saved?  If you're using non-persistent desktops, and it's being saved locally to the non-persistent desktop, then every time he logs off the desktop, it's going to reset and any changes (including the downloaded OST file) will be gone.

It's highly recommended NOT to use Exchange Cached mode with Citrix and non-persistent desktops.  You may have to use persistent desktops.

no I cannot change any settings, ost files through group policy are saved in network file server on one volume

ost files through group policy are saved in network file server on one volume

OST files should be kept locally and not on a network drive. This can cause issues with the OST files which is likely causing the problem you have.

how it can cause issues?

I tried to delete my comment as you are using Citrix.

OST's on remote storage are supported in an RDSH (Citrix) environment, hence why I think John said he was trying to delete the comment.

https://support.microsoft.com/en-us/help/297019/limits-to-using-personal-folders-pst-files-over-lan-and-wan-links talks about some of the requirements, such as high speed high bandwidth storage. Despite the URL, it does talk OST as well as PST. :)

Out of interest, how many users does it affect and why can't you switch to online mode? (Not arguing, just curious to the rationale)

Have you tried deleting their network shared OST completely and allowing it to be recreated?

few users are getting affected only, what is the meaning of network shared OST deleting, we deleted individual citrix profile  but that didn't help

Well when you use Outlook in offline (cached) mode it creates an OST file. If this OST is on a share somewhere, it's a network shared OST.

It's possible that this file isn't in the users' profile but in say their home drive. I would try deleting it an then launching Outlook again as it will recreate the OST from scratch.

This will rule out some corruption in the OST causing the re-download every login.

the ost file are being saved on  one file server x volume by group policy, so u mean change the path and save in their user profile instead

which is also on some file server , as c drive is hidden , the users dont have c drive