EV 12.5 items showing as 'ineligible' for archiving

Hi all

I’m trying to narrow down an issue whereby EV is archiving user mailboxes without error but mailbox sizes are not decreasing. At this stage I don’t think this is related to safety copies (which are kept in the original location) as backups are completing ok, trigger files are being actioned and the backup tab for the open partition being scanned as expected and items being secured. I do, however, think this may be related to a very large number of items being reported as ‘Ineligible under policy’ this figure can be many GBs and often represents approx. 80% of the user’s mailbox size – the worse case is a user with 14GB of ineligible items

I’m looking for a way to identify exactly what these items are and why they’re ‘ineligible’. I don’t believe this is due to message class exclusions as these are listed separately in the report and only represent a couple of 100MB of size. We do use shortcuts and these are configured to use the entire message body and shortcuts are not deleted. I’m happy to concede that existing shortcuts that go back years aren’t helping here but again don’t think this is the main issue as the report again shows the number and size taken by shortcuts which may extend to a GB or so but nothing more.

Can anyone provide some info on narrowing down the items that are being reported as ‘ineligible’ within a user’s mailbox? Will a Dtrace on the archiving task for a ‘run now’ against a user mailbox report this level of detail?

I have considered zapping the mailboxes but as this is affecting many users (albeit to varying degrees of impact) didn’t consider this a hidden message issue.

The EV environment is a single EV server running 12.5 which is used for MS Exchange archiving only from a single Exchange 2016 server. User run Windows 10 with Outlook 2016 and the outlook Add-In is 12.0

Thanks in advance