I have opened case 418-519-973, but wanted to see if anyone else has similar issues. Looking through the forum, I see a few unresolved cases that are similar.
XP SP3 with Office 2010 SP1. Test both 12.1.1000 & 12.1.1100 release.
Outlook auto-protect plugin installed and enabled.
When a user opens a large 2+MB file attachment, there is extreme unresponsiveness while outlook plug-in downloads and scans the attachment. Watching network traffic, this is capped at 0.40Mbps, only for the outlook attachment. All concurrent or newly started SMB file transfers are working at full capacity.
If I turn off the SEP Outlook plug-in, via Outlook, restart Outlook, then all attachments immediately start downloading at link speed (20-30Mbps) again. The same occurs if I run Outlook with the /safe string.
I can duplicate this over at least 4 separate hardware models, both laptop and desktop models.
This does not affect XP SP3, Office 2003 with SEP 12.1.000, nor does it affect Windows 7, Office 2010 with SEP 12.1.1000
For our environment, we cannot (read as will not) disable the Outlook plug-in, as it has proved valuable on multiple occasions. This is limiting our ability to upgrade users to Office 2010. Currently the support calls for slowness overwhelm those needing 2010 capabilities.
I have found that by enabling Outlook mail file caching, the issue is significantly reduced, since it's scanning off local disk, rather than streaming across the wire. Our Exchange admins prefer we do not utilize cached mode unless specifically required. They have their reasons why.
I can re-image machines and get the same result. Multiple rounds of uninstalls, repairs of Office, SEP, Adobe, etc. Each time, the same results.