Emails disappearing from Outlook/Exchange 2007

[simonns]

Hello, I have a user who started noticing some of his emails were not showing
up in his inbox. I have checked everything I can think of. Here is the run
down:

Emails seems to be random, some with attachments, some without. From
different senders. In some cases he already got many emails from the sender
in the past, even that day, but then one will not show up. The only
similarity I can see is that they are all external senders so far.

I have searched all his pst files and in OWA.

Message Tracking in Exchange 2007 says they got delivered to his inbox.

Emails are not in OWA, or in the deleted items in OWA.

There are no rules set up.

I have checked the views and filters, reset everything to default.

No spam settings set in Outlook.

User has one computer in cached mode and one not in cached mode. And neither
have the missing emails.

In one case he saw the notification bubble pop up on his desktop but the
email was not in his inbox.

No forwarding setup and nothing else strange in his account on Exchange.

So far it has happened about 9 times that we are aware of.

I am going to create a new profile for him today, and if that doesn’t work,
I’m going to delete and re-create his inbox.
Does anyone have any suggestions? Any help would be greatly appreciated.
Thank you.

-Simon Suster

 

[neo]

What are you using for antivirus software (server and client side)? Reason
I ask is that you may want to temporarily uninstall the client side
antivirus solution if it can scan e-mail to see if the issue stops. If it
does, see if you can reinstall the software w/out the e-mail scanning
portion as your server side solution should maintain a high level of message
hygiene.

 

[simonns]

Hi Neo, we use Trend Micro managed AV. I have looked at the trend spam
setting to see if this might be causing the issue. As far as I can tell, the
spam filtering is turned off. There are no spam folders in Outlook that get
set up with Trend, only the junk email folder which doesn't have any rules or
blocked email address listed. Thanks though, I am going to check trend
settings again.
-Simon