User receiving appointments acceptances from a shared mailbox calendar without having access

Brass Contributor

Oct 09, 2021

Many thanks for your reply.

I have already checked the MailboxFolderPermission on the Calendar folder and this person doesn't appear in the list (there are only the Default and the Anonymous users).
I tried with the

Get-CalendarProcessing -Identity <sharedmailboxname> | Format-List

but couldn't find any information about delegates. I noticed that there is a property called "ResourceDelegates", but if I run

(Get-CalendarProcessing -Identity <sharedmailboxname>).ResourceDelegates

I don't get any results.

I also tried the new switch parameter "ResetDelegateUserCollection"

Remove-MailboxFolderPermission -Identity "<sharedmailboxname>:\Calendar" -ResetDelegateUserCollection

but it didn't work, the user is still receiving the appointments acceptances.

It looks like his name is hidden somewhere but I can't find it. I checked also the Exchange Online Admin Center but to no avail.

Any other ideas?

Many thanks

Francesco

VasilMichev

MVP

Oct 10, 2021

Run a message trace against one of the invites, then look at the message trace details, they should give you a clue as to what's happening: https://docs.microsoft.com/en-us/Exchange/monitoring/trace-an-email-message/message-trace-modern-eac

fstorer

Brass Contributor

Oct 11, 2021

Hi VasilMichev,

I run the message trace against one of the invites (extended report), a csv file has been generated but I am not sure how to "read" all those information. I have a list of events, should I focus on the "deliver" event? I have many fields in the report, I have copied just a few below (removing IDs). Is there something in particular that I should check (server_hostname, connector_id, internal_message_id, reference, message_info, custom_data)? I also run the "Get-InboxRule" on the mailbox to check if there were some rules set, but I don't get any results.

Many thanks in advance

source_context	source	event_id	recipient_status	total_bytes
	RESOLVER	RECIPIENTINFO	UserMailbox.Forwardable.Resolver.CreateRecipientItems.40	26782
<number>;2021-10-08T13:27:38.234Z;10	SMTP	RECEIVE		26782
	MAILBOXRULE	RECEIVE	To	25625
<number>;2021-10-08T13:34:35.617Z;ClientSubmitTime:2021-10-08T13:34:25.000Z	STOREDRIVER	DELIVER		34820
Mailbox Rules Agent	AGENT	SUBMIT		25625
CatContentConversion	AGENT	AGENTINFO		28685

Forum Discussion

User receiving appointments acceptances from a shared mailbox calendar without having access