Recent Discussions
Will these commands fix our phantom meetings issue?
I opened a ticket with Microsoft Support for an issue we are facing where "phantom" meetings are appearing in at least two of our meeting room calendars. The subject of the meeting says "Private appointment" and the lock icon appears at the bottom, and when you click on any of them they disappear from the calendar, only to re-appear when you navigate away and come back. They appear in Classic Outlook, New Outlook and Outlook for the web. The support rep is telling me to run these commands on the room mailbox to "reset the room mailbox availability cache": Set-CalendarProcessing -Identity <roommailboxupn> -RemoveOldMeetingMessages $true Set-CalendarProcessing -Identity <roommailboxupn> -AutomateProcessing AutoAccept But if I run Get-CalendarProcessing, it confirms that these are the existing settings already: Get-CalendarProcessing -Identity <roommailboxupn> | fl RemoveOldMeetingMessages,AutomateProcessing RemoveOldMeetingMessages : True AutomateProcessing : AutoAccept This can't possibly do anything, right? I should ask my CSAM to open a GetHelp on this case, right? Does anyone know how to actually fix this issue?
Disabling Calendar Repair Assistant on mailboxes in Exchange Onprem 2019
Hi, We are in Exchange Hybrid setup were some mailboxes are in cloud and onprem. Recently, there were some issues with Calendar events were recipients weren't notified of any updates for the events, sometimes the updated event would have been cancelled by recipient and the recipient didn't even know that they received update and it was automatically cancelled by them.... This was a normal situation for EAs for their executive calendar events When raised a ticket with Microsoft on this issue, Microsoft collected CDL logs and found that CRA was kicking in each time when there was an update and was reverting the updated meeting request to the previous cancellation and as we know this is not a bug, this is just how the CRA works...So, Microsoft is like CRA is a legacy feature with limited applicability and functionality in the current exchange environment and hence has asked to disable-CRA in On-prem exchange as this will not affect normal calendar usage for users. I had disabled for 5 users and they have reverted that they are not seeing any issues post disabling CRA. so before gunning down on all mailboxes I wanted to take a second opinion on whether is it safe to disable CRA for alll mailboxes in Exchange OnpremHigh Volume Email is Generally Available and Ready to Charge
On April 1, Microsoft announced the general availability for the High-Volume Email (HVE) solution together with details of the PAYG charges incurred to send email to internal recipients, which is all that HVE can do. Microsoft will enable HVE charging on June 1, 2026, Before then, you’ll need to create a billing policy and link it to a valid Azure subscription if you want to continue to use HVE. https://office365itpros.com/2026/04/23/hve-ga-charging/Is the Archive mailbox self-help diagnostic working for anyone?
Just curious: is the archive mailbox self-help diagnostic at https://aka.ms/PillarArchiveMailbox working for anyone? When I run it, instead of getting results about the user whose UPN I entered, I get this: The following issues were found with your archive mailbox. No account was found for [The UPN of my admin account]. Make sure you've entered the correct email address or create a new account with that name. For more information, see Add users to Office 365. I tried opening a ticket with Microsoft Support, but they refused to work on it without requiring me to do all the legwork of gathering logs and HAR traces and who knows what else, despite the fact that the support agent was able to replicate the exact same issue in his lab.
User cannot rename categories even when being the owner
Hi guys, I have a user that cannot rename categories in a mailbox whilst being the owner. As you can her permission level is set on owner. And yet the rename is greyed out: User says she was able to rename just some time ago, but when she tried on 17/04/2026 she couldn't. Anyone has any ideas?
Email Showing as Quarantined in a Message Trace, but Not Showing up in MS Defender
A customer of ours was waiting on an email to arrive and to help figure out where the email was or if it was sent yet we ran a message trace. The message trace showed that the email was sent to quarantine. With this information in mind, I went to MS Defender > Email & collaboration > Review > Quarantine but could not find the message. I modified some of the filters and could not get the quarantined message to appear. I triple checked the filters I created and made sure the information was correct. I also removed all filters and looked for the time period the email came in, but could not find it. Not sure if this is related, but this email had a significant delay likely coming from the sender. Any thoughts or ideas? Or anything that I am missing?Administratively retract a user's email
I was recently asked to retract a message that was sent in-error to staff. I ran a discovery/search, and saved it, but when I ran the powershell script after connecting to Exchange, the script could not find the search, something like name not found. I verfied the name was correct, and I am a global admin so permissions should not have been an issue. Does anyone know of any accurate documentation to run a search and retract? I had to use an old YouTube video and could not find anything in Microsoft's documentation.
ARC verification fail (40) on specific Exchange Online frontends - recurring issue
Hello, We are observing recurring arc=fail (40) errors on messages forwarded through Exchange Online, caused by specific frontend servers. The same messages pass ARC verification correctly on other providers (Google, etc.). Affected frontends identified so far: CH2PEPF0000013F.namprd02.prod.outlook.com - build 15.20.9700.17 (March 14, 2026) CH3PEPF0000000B.namprd04.prod.outlook.com - build 15.20.9769.17 (April 6, 2026) Both share the same build suffix .17. The signing implementation on our side has been cryptographically verified as correct and RFC 6376 compliant. The issue has also been reported on the IETF ietf-smtp mailing list with full technical analysis. Cryptographic analysis shows the failing servers append a spurious trailing \r\n to the last header before computing the verification hash, violating RFC 6376 Section 3.7. Is there a pattern with .17 frontend builds and ARC verification? Reagards Vittorio
Microsoft Exchange Report
I faced a new issue today, don't know if anything breaks at Microsoft or any new thing roll out from there, the things is unable to check usage report properly as well as unable to export the email activity, Mailbox Usage etc report under report- exchange and other tabs as well in customer tenant. I have Global Reader privilege but still facing this issue. Anyone faced this type of issue from today or before? If anyone knows about its pleas update your comment here. Thanks..iOS 26.4 iPhone Contact Sync with Microsoft Exchange Online
For the past 2–3 weeks, several of our iOS users have been experiencing synchronization issues with Exchange contacts. Contacts intermittently disappear from their devices and then re-sync after some time. In some cases, the re-synchronization process is significantly delayed. Anyone else experiencing the same issue?
Preserving permissions during EXO migration
Hi, Can you help me understand the outcome of preserving the permissions in our scenario. Exchange Server 2016 (soon Exchange SE) in a hybrid with Exchange Online. We are moving 75% of the mailboxes to Exchange Online. What ways will preserve or break the full-access or sendas permissions? I guess best way would be to migrate both the user and the shared mailbox at the same time in the same batch to keep the permission? If we migrate the user in batch 1 and shared mailbox in batch 2 will that preserve/break the full access/send as? If we migrate the shared mailbox in batch 1 and usermailbox in batch 2 will that preserve/break the full access/send as? If the permission is linked directly on the shared mailbox or via a security group is there a difference? Thanks!Microsoft Limits App Access to Sensitive Message Properties
Microsoft has announced details of a change to app permissions to restrict updates to sensitive message properties (like recipients) without consent for a new advanced mail access permission. If tenants have apps that interact with message properties, including apps developed by third parties, they should check whether the apps are updating sensitive properties. If so, the new permission must be assigned or the apps will stop working. https://office365itpros.com/2026/03/26/sensitive-message-properties-graph/
Can we hide default address lists in Outlook Address Book and show only custom ones?
There are existing Custom Address Lists. When users use the MS Outlook App (Office 2019) and open the Address Book, is it possible to hide the other address lists (including domain-sg-GAL, Global Address List, and domain-sg-Rooms), and only display the Custom Address Lists (domain-HK-AL and domain-sg-AL) — the ones shown in green in the photo?
Issue with certificate renewal for exchange Edge Transport Server
Hello team, I have come across a very particular problem I deployed 2 exchange server 2019 with one edge transport server When we are renewing the Certificates with wildcard certificate on both mailbox server ,and on edge transport server ,it is impossible for me to renew the edge subscription It says the cerificate is in "doublon" (repetitive) on one of the Exchange servers.I have always been using same certificate on exchange server be it edge or mailbox I tested a bogus different certificate on mailbox and on edge,only then th e edge sync works Did anybody come across this issue. ThanksAdd-PublicFolderClientPermission: Object reference not set to an instance of an object.
Running into an issue with adding public folder permissions in Exchange Online. I've used this PowerShell script for a few years without any issues, but suddenly getting this error no matter what I try. I do have Owner permissions and there are Default and Anonymous permissions on the public folder, tried completely removing and reinstalling the ExchangeOnlineManagement module as well. Anyone else having this problem? $PF = Get-MailPublicFolder -Identity "\pf1" $User = Get-User -Anr "User1" $AccessRights = @( "ReadItems", "CreateItems", "EditOwnedItems", "EditAllItems", "FolderVisible" ) Add-PublicFolderClientPermission -Identity "\$($PF.Id)" -User $User.UserPrincipalName -AccessRights $AccessRights -Verbose VERBOSE: Returning precomputed version info: 3.9.2 VERBOSE: Requested HTTP/1.1 POST with 227-byte payload VERBOSE: Received HTTP/1.1 response of content type application/json of unknown size VERBOSE: Query 1 failed. Add-PublicFolderClientPermission: Object reference not set to an instance of an object. Thank youEmails from Azure Communication Services (ACS) are treated as external emails
When using Azure Communication Services (ACS) Email, messages are delivered to Microsoft 365 as external mail, even if the system sending them belongs to my own organization. This behavior can be expected because ACS sends emails from Microsoft’s cloud infrastructure rather than directly from my tenant. As a result, Distribution Groups (DG), Dynamic Distribution Groups (DDG), or Mail-enabled Security Groups (SG) that are configured to accept messages only from internal senders will reject these emails. The common workaround is to enable “Allow external senders” on the group. However, we don't want to open the group to the entire internet. Does anyone else have the same experience? What is the best solution, exchange transport rules? Thanks!Microsoft Rushes High-Volume Email to General Availability
Almost two years after it first previewed, Microsoft is making the High-Volume Email (HVE) solution generally available in March 2026. HVE runs on a pay-as-you-go basis, but Microsoft won’t start charging tenants for sending email until May 2026. Two months should be enough for people to decide if they want to use HVE for internal communications as it has no ability to send external email. https://office365itpros.com/2026/03/09/hve-ga/Measuring KPIs like Response Times for Shared Mailboxes
Shared mailboxes are not CRM systems. However, many Microsoft 365 tenants use shared mailboxes to handle customer queries and then want to measure KPIs such as agent responsiveness to customer queries or the number of queries handled per agent in a month. As explored in this article, it’s possible to use the Microsoft Graph and PowerShell to extract some KPI-like data from shared mailboxes. https://office365itpros.com/2026/03/05/shared-mailbox-kpi/Proper whitelisting of microsoft.com on dnswl.org
I keep having the issue that system-generated e-mails, e.g. on Trace Reports get classified as spam by the receiving e-mail provider. The sender address is email address removed for privacy reasons and the e-mails go to my M365 mailbox and are redirected to my external monitoring mailbox with that e-mail provider. The e-mail provider calculates a score that includes checking the sender's IP address 52.101.69.91 with dnswl.org . Unfortunately, that address is only whitelisted for outlook.com and some secondary domains, but not for microsoft.com. Of course, the issue also occurs with mailto:email address removed for privacy reasons and other IP addresses, so this is an example. It started to occur around two weeks ago, not sure if the provider changed policies or Microsoft changed the whitelisting; of course the provider refuses to overrun dnswl.org it, e.g. by own whitelisting. Who at Microsoft could I ask to fix that kind of issues? I don't find any appropriate category in their support menues, M365 support says the cannot help (TrackingID#2603031420001611). Thanks in advance for any hints, this is my first posting here, so please forgive me, if this is a dumb question.
Recent Blogs
- We wanted to provide a few updates related to modernizing DNS Security in Exchange Online.Apr 23, 2026
- 2 MIN READWe wanted to tell you about a new Change Optics Report that is now in Public Preview.Apr 20, 2026
