Any Microsoft Exchange experts on here?
Like many places we use Outlook/Exchange where I work. Just recently a new distribution list has been set up for a group of us to use for something.
No, I can see a list of members of the distribution list. Thing is, the e-mails to the DL seem to be going to additional people who don't show up in the list of Members visible in the Outlook address book or if you expand the list when the DL is in the To: field in an e-mail message.

This distribution list is meant to be confidential so I'm rather concerned that messages being sent using it are going to hidden additional recipients.
I've been googling how this would be achieved but I don't really know what I'm looking for. So, any Exchange experts able to shed any light on what's going on here?

Theoretically not possible.

If they aren't appearing in the DL, then they won't receive the email. They have to be in the To, Cc or Bcc field to receive a copy.

Either somebody is sending them on or they are adding them to the Bcc field.

Agreed. Most likely BCC which won't show in the headers of the email (that's the point) or someone has an inbox rule maybe to send them on to the 'third party'. There's outside possibility one of the people sending email to the list has a corrupted contact that may be making wonkey things happen - are all the emails that end up in the wrong place coming from one particular sender, or is it any email in the list?

I'd suggest using the Exchange message tracking feature 'backwards' - for one of the people who received it but shouldn't have. Basically get an example email, and 'track' in their mailbox for any email with that subject. That will tell you who sent it to them and therefore you have to check for inbox rules etc. It depends on what version of exchange it is exactly what else you can get & that's probably going to be something you'll need to do some powershell tinkering to get to.

If the person that sent it to them was the original sender of the email... As Dave says, theoretically impossible, but in that case I'd delete the dist list and rebuild it. It is a manually managed list or a dynamically generated one based on an AD group/context etc?

Thanks for the info guys.
Unfortunately I don't have any access to the servers to find out whats going on (I don't work in IT).

The distribution list in question is for use by the employee reps on the staff council. Someone noticed that a message to the list also appeared to get delivered to a manager who isn't part of the group (and whose name doesn't appear in the DL).
The concern is that IT have added something to the DL or some sort of server rule that distributes messages that should be confidential to the Reps to managers as well.

It could be done with mailbox rules. But that means one of the other recipients has a rules set up that forwards the message to the manager - either all messages or specific headers, senders etc.

He could do that or IT could do it in the background, but would find themselves on dodgy ground if they did. If it is done at the request of a manager, he could find himself in hot water as well. Not sure on UK DP law, but certainly here, it would be illegal and the manager and the person in IT who did the redirect would be candidates for dismisal or prosecution.

But if the name isn't appearing in the list, then it doesn't have anything to do with the list.

Could be transport rules or journalling at an exchange level.
or mailbox permissions.

There's so many ways to do it, you just need server access to find it out.

Indeed. without access to at least the server logs and the Exchange configuration, you're pretty much on a hiding to nothing.

Does anybody who is not in the distribution list have any rights to the mailbox of someone who is in the list? If so, wouldn't they be able to see emails sent to the DL?

That's what I'd be checking, using the Exchange Admin Center, (yes, American spelling)

Or am I talking BS... again?

It's possible, but it would generally be rather obvious if they were seeing it that way rather than it actually being delivered to the wrong person. I wouldn't expect people to get the two things confused.


Whether there's an Admin center or not depends on the version of Exchange they're running. Believe me, there are some very old setups still going out there

Depending on how many people are in the distribution list, I still think it's worth checking their mail account settings to make sure that nobody has access to their mailbox that shouldn't.

Log into your OWA > options > groups and see if you can remove and then re-add yourself.
The guy may have been in the group at the time that email went, but then taken himself out once he 'realised his mistake'.

Mystery solved!

The e-mail poped up on the managers screen because they were viewing a Web-Ex meeting and the person organising it (who is on the distribution list) received the e-mail and the notification popped up on their screen (so the e-mail notification appeared on the shared screen).

Phew.

Thanks for all the responses guys.

We had a tech rep from another company in earlier this week, demo'ing some kit, using his laptop, connected to the big screen.

He received an email notification pop up balloon, (we think it was from a friend of his) with something along the lines of "click this link, it may be interesting"

A few moments later, a second balloon appeared, from the same "friend" with these words... "Oh, and lick my balls"

Oh My God.