Trying to block zip files with O365 seems a little painful, as the default GUI does not really give you the option (anymore?) If you Google, you might find screenshots with options to select the attachment but when I checked our GUI, that was all that I saw:

Clearly, there is no option to look for attachments, other than what the attachments CONTAIN.

So, trying PowerShell, something interesting happened.

Executing this PowerShell command, it created a new rule, that now had more/different options than the rule you could create from the GUI!

Look at this:

And now you can block file extensions and stuff to your heart’s content.

Oddities ¯\_(ツ)_/¯

We had a $user who deleted ALL emails from a shared mailbox and you might notice that the option to recover deleted items is grayed out and you cannot select it.

We need to set a registry key to turn that option on.

Create a new DWORD value with the name ‘DumpsterAlwaysOn’ and a value of 1.

Easy via PowerShell:

You have to close Outlook and start it again and voila, you can restore items.


Want to use PowerShell on your CentOS box? Easier than ever!


Grr run into this before, you create a new folder, give it a new name and somehow your cluster thinks, nah we already have that in there. I double and triple checked ‘Share and Storage Management’, there was no shared folder like that for sure.

Well, good ‘ol regedit to the rescue.

And indeed, for some odd reason, there was a key with that name in there.

If you find a share that doesn’t belong, you can delete the key for the share on all nodes.