Outlook OST corrupt error

Hello

We are seeing issues in our outlook 2013. Outlook will hang and then user force to quit the application, then when we try re-launch the outlook application we get outlook.ost is corrupted error. But if we restart the machine the same OST file works fine for few hours and the same issue happen again.

For testing we uninstalled the Sophos Endpoint from the machine and the issue is disappeared, Below are the details about our setup.

Windows 10  version10.0.19042.867

Outlook 2013 Version 15.0.5327.1000

Exchange 2013 CU 23

Sophos Endpoint Agent 2.15.4

Is anyone seeing this behavior please update me.

  • Hi,

    How many systems are currently experiencing the said issue? Before proceeding on removing the AV have you tried to perform a repair OST using OST repair tool which is built-in from MS office application? You may try this first and see what happens. If the issue persist, you can follow this Article for basic troubleshooting. for you to Identify what components cause the issue.

    GlennSen 
    Community Support Engineer | Sophos Technical Support
    Sophos Support Videos | Product Documentation | @SophosSupport | Sign up for SMS Alerts
    If a post solves your question use the 'Verify Answer' link.
  • We've been troubleshooting .ost corruption issues on desktops and laptops, Win 8.1 and 10, and Outlook via Office 365 going back almost 2 years to present. We've dug into countless areas, opened tickets with Microsoft, logged everything imaginable and we cannot determine the root cause. One of the only consistencies for us is that all laptops and desktops are running Sophos Endpoint, recently upgrading and enabling Intercept X.

    Today, I just happened to stumble upon this post (and a few others) and decided to add a global exclusion in our Sophos configuration for *.ost to see if this makes any difference. It could be that Sophos is entirely unrelated, but this issue has impacted probably a dozen users anywhere from once every few weeks to a couple of times per year.

    Yes, it's largely an annoyance as we just delete the .ost and let Outlook recache, but for some folks with very large mailboxes (and who like to have as much offline as possible), it can take a day+ to re-cache their mailboxes.

  • Yeah you can add the wild card on your exclusion and observe if there’s n improvement. 

    GlennSen 
    Community Support Engineer | Sophos Technical Support
    Sophos Support Videos | Product Documentation | @SophosSupport | Sign up for SMS Alerts
    If a post solves your question use the 'Verify Answer' link.
  • Update: We made this wildcard change last week and over the weekend we had another instance of a user .ost corruption, so it doesn't seem like Sophos is related.

  • Thank you for your confirmation, have you tried reducing the size of the OST file by archiving them as PST? let say, you'll try advising users to always archive their mails every after 3-5 GB OST size. You may also perform a cleanup of their OST there might be lots of deleted emails residing on a deleted folder which adds the size of the OST file. 

    GlennSen 
    Community Support Engineer | Sophos Technical Support
    Sophos Support Videos | Product Documentation | @SophosSupport | Sign up for SMS Alerts
    If a post solves your question use the 'Verify Answer' link.
  • I did raise the support ticket with Sophos and Installed latest hotfix Current Hotfix Version: 3.8.2.292 yesterday. We are monitoring the clients machine for past 24 hours no issues reported. 

  • I appreciate the suggestion! While I have a suspicion that the overall size of the files is contributing to the issue, we have a lot of folks who "need" to have offline access to their mail. In addition, I had experienced ZERO .ost corruption issues with huge mailboxes and 100% of the email cached (we're talking ost files in the 50-75GB range) until ~January 2019 after an Office 365 patch for Outlook 2016.

    The specific example that triggered this support forum post had a user with a 45GB .ost file, we re-cached Outlook and all was good, but his Windows Search Index .edb file had grown to 78GB, which is yet another known issue with Outlook and the Windows Search Index. I re-indexed his .edb file and THAT caused ANOTHER Outlook .ost corruption event, so it's very possible there is something going on between Windows Search and Outlook that is either the root cause or a large contributor to the issues we've been facing.

    I suppose another thing I can try on the users who experience the most frequent corruption is to uninstall Sophos, but I am now less confident Sophos is related in any way. (It was installed throughout our organization before the .ost corruption was occurring more regularly.)