Background

Zimbra is an add on for Outlook (we still aren't entirely clear on what it does, but we've seen a handful of sites using it).  When the Zimbra connector is installed, and the Zimbra Outlook profile is selected, the Attach Plus paperclip integration will not work.  Send To integration still works properly.

If the user changes the Outlook profile to something besides Zimbra, then the paperclip integration works properly.

Here is a screen shot showing the Profile selection dialog in Outlook:

 

Our analysis of the issue clearly points to a bug of some sort in Zimbra that prevents 3rd party applications from integrating properly when the Zimbra profile is selected.

Workaround

Use Send To integration

Resolution

At this point, we have no solution other than not using Zimbra.  We suggest that you contact your Zimbra provider and file a support ticket with them asking them to resolve this issue.

We have opened the following ticket with Zimbra - if you comment about the effect this bug has had on your productivity, it may get attention:  http://bugzilla.zimbra.com/show_bug.cgi?id=74598

Update:  We have seen development progress on this issue in the Zimbra bug tracker. If you hit this issue, you may want to get the latest version of Zimbra and see if that helps.