We are using a Release Candidate of v4 at the moment & I'll upgrade to 4.02 when I can, so this issue might be just in the version we are using.
Would someone mind trying to send an attachment to someone using Zimbra a release version of v4 with an apostrophe in the file name?
HTTP Status 404 - no such item when clicking on the attachment.
We have a user who has someone sending attachments regularly to them who likes using apostrophes in file names quite a lot.
For now our workaround is to connect Outlook via IMAP and just open Outlook when one of these comes through.
The user is sure that such attachments used to work prior to v 4